Jim Hurrell, Senior Scientist
Climate Indices ->Data
Winter (Dec-Mar) Station Based NAO Index
The winter NAO index values are given in the table below. (Missing Value = -99.) Note: The station index value for year N refers to an average of December year N-1 and January, February, and March year N. (Example: The 1899 value contains the average of December 1898 and January, February, and March 1899.)
The winter values are also available as two columns (year and value) in the following formats: ascii | Microsoft Excel File (.xls)
00 01 02 03 04 05 06 07 08 09
1860 -99. -99. -99. -99. -1.02 -1.24 0.54 -1.38 2.81 1.70
1870 -3.01 -1.01 -0.76 -0.50 2.32 -1.35 0.21 0.05 1.46 -2.22
1880 0.89 -3.80 3.87 -0.23 1.44 -0.89 -1.12 0.45 -2.75 -0.01
1890 1.78 -0.82 -2.02 -1.07 2.68 -3.97 1.12 1.09 1.02 0.03
1900 -2.13 -0.33 -1.41 3.89 0.23 1.98 2.06 2.06 1.44 0.00
1910 2.10 0.29 0.24 2.69 1.48 -0.20 -0.69 -3.80 -0.80 -0.80
1920 3.18 1.63 1.85 1.73 -1.13 2.39 0.11 1.72 0.63 -1.03
1930 0.91 -0.16 -0.50 0.25 0.86 0.97 -3.89 0.72 1.79 0.37
1940 -2.86 -2.31 -0.55 1.48 0.61 1.64 0.27 -2.71 1.34 1.87
1950 1.40 -1.26 0.83 0.18 0.13 -2.52 -1.73 1.52 -1.02 -0.37
1960 -1.54 1.80 -2.38 -3.60 -2.86 -2.88 -1.69 1.28 -1.04 -4.89
1970 -1.89 -0.96 0.34 2.52 1.23 1.63 1.37 -2.14 0.17 -2.25
1980 0.56 2.05 0.80 3.42 1.60 -0.63 0.50 -0.75 0.72 5.08
1990 3.96 1.03 3.28 2.67 3.03 3.96 -3.78 -0.17 0.72 1.70
2000 2.80 -1.89 0.76 0.20 -0.07 0.12 -1.09 2.80 2.11 -99.
Note: The values in the above table differ slightly from those in Hurrell (1995) because of continual updates to the data and a change in the base period. The SLP anomalies at each station were normalized relative to the 120-year period 1864--1983. Hurrell (1995) normalized relative to 1864--1994.(Hurrell (1995): Science 269:676-679)
Note #2: The 1997 value was changed from -0.20 to -0.17 after it was discovered that the WMSSC December 1996 SLP value for Reykjavik had changed. It was initially reported to be 1014.0, and had since been corrected to 1013.3hPa.
Return to Climate Indices Table
Monthly Station Based NAO Index
Monthly index of the NAO based on the difference of normalized sea level pressures (SLP) between Ponta Delgada, Azores and Stykkisholmur/Reykjavik, Iceland since 1865. (Missing Value = -99.)
J F M A M J J A S O N D
1865 -0.6 -1.2 0.2 -0.2 -0.4 0.0 0.5 1.5 1.8 -2.0 -0.9 0.8
1866 0.5 0.8 -0.6 -2.3 -2.0 0.9 -0.5 -0.2 2.4 -0.3 -0.5 0.2
1867 -3.5 1.1 -4.3 1.8 -4.2 0.1 -2.0 1.9 1.4 2.2 -3.5 -0.1
1868 0.7 3.0 3.6 1.7 2.3 3.1 0.4 1.5 -2.8 3.5 -1.8 -0.1
1869 1.0 2.5 0.2 -0.2 -2.7 -1.9 -0.3 -1.0 -0.4 -1.4 1.4 0.0
1870 0.4 -2.8 -2.0 1.1 1.5 0.3 0.5 -3.6 0.2 0.9 -2.1 -3.0
1871 2.0 -0.3 0.9 -2.6 -1.5 -0.9 0.8 0.0 -2.2 0.2 -3.1 1.1
1872 1.0 -0.7 -1.1 -0.5 1.0 0.2 -2.3 -2.4 -1.8 1.6 0.4 -0.5
1873 1.3 -0.6 1.2 -3.3 -0.9 1.9 -0.1 3.1 -2.2 1.7 -1.9 0.6
1874 1.5 0.9 0.9 2.0 -1.3 0.1 0.6 0.9 1.4 1.8 -0.2 0.1
1875 -0.7 -1.0 -0.8 -1.8 2.4 3.2 -1.1 -1.6 -1.5 0.1 -3.1 -0.6
1876 0.8 -0.7 0.5 -0.6 0.8 3.3 1.7 0.3 -3.7 -1.9 -4.4 -2.1
1877 0.9 1.1 0.1 -3.1 -2.8 -0.1 1.3 -5.5 -3.2 0.0 2.2 2.5
1878 0.5 -0.2 0.2 -2.7 -0.8 -1.2 0.4 -3.5 1.0 -1.4 -3.1 -5.5
1879 -0.9 0.9 1.2 -0.2 1.6 -1.4 -0.4 -0.7 2.9 -0.3 -3.9 -1.2
1880 -0.8 1.0 0.5 1.3 -0.6 -0.2 -3.6 -0.4 -1.1 -4.7 1.0 -2.2
1881 -5.9 -0.9 -2.3 -1.9 0.9 1.2 1.7 -0.9 -2.2 -0.9 1.4 2.7
1882 1.0 0.6 3.6 -1.3 -1.3 0.1 1.8 0.7 1.6 0.3 1.6 -1.4
1883 0.7 2.4 -2.4 1.3 1.3 -2.3 -2.5 1.3 -0.7 2.5 1.9 0.7
1884 0.7 0.8 1.3 -2.0 0.3 0.9 -3.0 0.9 1.4 1.4 -1.1 2.1
1885 -0.4 -1.8 0.9 1.2 -1.6 1.7 0.3 -4.9 1.9 -0.3 -1.2 -1.3
1886 0.3 -0.1 -0.9 -1.2 -1.2 0.8 0.7 3.0 -1.2 0.7 1.6 -0.2
1887 1.7 1.1 -1.9 -3.2 0.5 -2.0 -0.3 -2.3 -0.7 -3.3 -1.1 -2.7
1888 -1.5 -1.6 -1.5 -0.8 -1.5 -1.7 -1.7 -0.4 -3.0 -3.1 2.2 1.4
1889 1.2 0.2 -0.2 1.7 0.5 1.7 -3.0 1.5 -1.2 1.0 1.7 3.1
1890 2.3 -0.7 2.0 1.8 -0.6 1.7 1.4 1.1 1.3 0.0 2.7 -0.8
1891 0.2 0.9 -1.2 -1.6 -0.8 -4.0 -2.8 0.2 1.6 1.1 0.0 1.7
1892 0.5 -1.8 -1.4 -0.6 -2.2 -1.6 0.0 -0.2 2.2 -3.2 0.7 -1.3
1893 -2.1 0.8 -0.4 -0.2 -1.2 -2.6 0.2 -2.8 1.7 0.4 -2.3 2.3
1894 0.5 3.1 1.7 1.8 -0.8 2.7 1.2 0.3 -4.0 -3.1 2.2 0.6
1895 -1.7 -4.9 1.0 -0.7 0.6 -0.4 0.1 -0.5 0.1 -2.8 -0.6 -0.5
1896 -0.9 0.9 2.6 2.5 1.2 -0.6 2.3 0.0 -0.1 -2.5 -0.9 1.8
1897 -1.5 1.1 1.0 3.6 0.1 -2.6 -1.0 1.4 1.0 -2.1 -0.5 0.6
1898 1.2 1.2 -0.5 2.2 -1.1 -1.5 -1.5 1.1 -0.8 -0.9 0.9 0.6
1899 -1.3 -1.6 -2.1 -0.3 -1.4 1.4 2.0 -2.6 1.4 -2.0 0.6 -0.9
1900 1.8 -3.1 -2.1 0.8 0.7 -0.7 -1.0 0.5 2.3 -0.3 2.2 1.2
1901 0.0 -2.9 -0.6 1.3 -1.7 1.6 1.2 1.0 1.2 2.0 -2.4 0.1
1902 -0.3 -2.8 0.7 -1.9 0.9 -4.0 -2.4 -1.6 -2.2 0.5 0.0 0.6
1903 0.1 1.8 3.6 -0.1 1.2 -3.6 -0.3 0.8 -0.6 -0.9 0.8 0.5
1904 1.8 0.9 0.6 4.1 0.8 -0.7 -1.6 -1.9 1.1 0.2 -0.5 -1.3
1905 0.4 1.4 1.7 -1.7 1.4 -0.7 0.5 0.5 1.3 -1.9 0.9 -0.3
1906 1.8 1.8 -0.4 2.5 -2.9 -1.6 2.9 -1.8 1.2 1.5 0.1 1.5
1907 0.8 1.6 3.2 1.6 -2.8 0.7 -2.4 -0.5 -0.1 0.1 1.8 0.6
1908 0.9 2.0 2.3 -1.2 1.1 1.1 -0.4 -0.4 0.3 -1.0 0.2 1.8
1909 1.4 -0.1 -1.9 0.4 -2.1 -0.9 3.3 2.5 -1.6 2.1 -1.9 -2.5
1910 2.0 3.4 1.7 -1.0 2.6 0.4 -0.6 -1.3 -1.3 -0.8 -1.9 -0.4
1911 0.8 0.8 0.2 -0.7 3.2 0.0 -1.8 -1.0 -0.1 -0.7 0.5 0.9
1912 -1.1 -2.4 1.9 1.1 0.6 0.0 -0.7 -1.4 -2.3 1.5 0.9 1.9
1913 0.5 0.3 3.1 2.7 1.3 1.7 -1.0 1.0 -1.6 -1.9 3.6 0.3
1914 -0.5 1.4 1.3 1.4 2.8 2.4 -0.5 0.7 -0.2 -0.4 0.1 1.4
1915 0.8 0.9 -3.2 3.1 -2.7 -2.6 0.3 -2.6 -2.0 1.4 -2.8 -2.7
1916 2.0 1.9 -3.0 1.0 -0.3 -1.9 0.4 -1.6 -1.1 2.4 -0.3 -3.7
1917 -2.3 -1.2 -0.4 -2.6 -2.8 0.5 -1.7 -0.4 1.8 1.8 1.7 -1.8
1918 -4.5 2.5 0.8 -0.4 0.4 1.5 -3.0 1.2 0.8 2.0 0.3 0.7
1919 0.0 -2.7 -0.4 1.0 -0.7 3.3 -1.2 1.0 0.8 -1.2 -1.6 2.3
1920 2.3 1.0 3.6 -1.8 2.3 -0.3 3.1 -1.0 1.3 -0.2 2.1 -1.8
1921 1.6 0.3 3.1 -0.5 2.8 -1.0 -1.2 0.8 -0.2 -1.2 -0.6 2.7
1922 0.6 2.6 0.5 -0.1 1.4 2.9 2.0 1.6 1.7 -3.7 -0.3 0.8
1923 1.5 0.8 0.0 0.5 -0.8 0.8 2.4 0.2 1.8 1.3 0.2 1.2
1924 0.4 -0.8 -3.5 -2.2 -0.3 -0.1 1.5 1.8 1.2 0.7 0.6 2.8
1925 1.0 2.0 -1.1 2.1 1.8 1.1 2.7 1.1 -0.1 -1.6 -1.6 -4.3
1926 0.3 0.4 0.2 0.9 -1.4 -1.8 0.7 0.8 -1.1 -2.8 2.1 -0.9
1927 1.9 0.3 1.9 0.9 -2.3 -0.2 -0.3 0.2 0.0 -3.2 0.5 -3.5
1928 3.0 1.7 -1.0 0.8 -3.1 -2.9 0.8 -1.5 -1.0 2.0 1.7 0.6
1929 -4.1 -0.3 -1.4 -3.0 2.3 -0.7 -0.1 0.3 1.3 1.9 1.9 2.6
1930 1.4 -0.2 -1.1 -0.3 2.5 2.8 -0.5 0.0 -2.8 0.6 1.0 2.1
1931 -0.1 1.8 -3.4 1.1 -0.7 -1.9 2.1 -1.9 -1.4 -0.9 2.4 0.0
1932 1.1 -3.5 -1.3 0.7 -1.5 -1.3 1.8 1.6 0.3 1.8 0.5 0.1
1933 1.5 -2.1 0.7 -1.9 0.3 2.2 2.3 1.8 -0.4 -2.1 0.3 -0.6
1934 1.7 0.6 2.2 -2.0 2.8 -2.0 0.4 2.4 2.1 0.9 -0.5 -1.1
1935 -0.1 2.2 0.2 -2.0 -1.8 0.8 3.8 2.0 0.4 3.6 1.7 -1.7
1936 -3.0 -2.6 -0.9 -0.9 0.9 0.5 1.1 2.1 -2.3 2.4 1.9 1.3
1937 0.6 0.1 -2.0 1.0 1.7 -0.6 -0.1 1.3 1.4 -0.6 -3.1 -1.1
1938 2.2 -0.8 2.4 -1.9 1.1 1.3 2.2 1.3 1.6 3.8 2.1 0.7
1939 -2.1 2.2 0.7 -0.4 0.3 -0.4 -0.6 1.3 -4.0 -0.6 1.5 -1.7
1940 -2.6 -2.1 -1.5 -0.5 -0.2 1.8 0.6 0.7 0.1 -0.2 1.5 -0.1
1941 -2.9 -0.9 -0.9 -1.7 0.3 0.3 1.7 0.2 -1.2 -1.1 -0.2 0.8
1942 1.6 -2.7 -2.0 -0.4 -0.1 -2.0 1.5 1.8 2.1 1.0 -1.5 0.3
1943 -0.7 2.7 0.7 3.4 0.6 0.7 0.4 -1.6 2.6 0.8 1.6 1.1
1944 1.0 -0.2 -1.8 -0.4 0.7 -0.4 -3.0 1.7 1.1 2.0 0.5 1.2
1945 -2.2 2.5 0.8 -2.2 -0.3 0.5 0.2 1.4 0.5 -1.9 -2.9 -2.1
1946 1.4 -0.2 0.2 3.0 -2.5 2.7 2.3 2.0 1.3 -2.7 -0.9 1.6
1947 -0.2 -4.2 -2.8 3.3 -0.2 -0.1 0.5 -0.2 2.4 -0.2 -1.9 -2.1
1948 0.6 -0.5 2.0 1.6 -0.4 -0.4 -0.6 -0.2 0.1 1.5 -1.6 -0.5
1949 0.9 1.9 -0.2 2.5 -0.1 -1.7 -0.8 -1.1 -0.8 0.1 1.6 0.4
1950 0.0 1.5 0.0 1.6 -2.2 -0.1 -0.1 1.4 3.0 1.2 -0.6 -1.0
1951 1.0 1.4 -2.1 -1.6 -1.8 -2.8 -0.3 2.2 0.2 1.5 -0.1 2.4
1952 2.0 -1.2 -2.1 2.2 -2.0 -0.2 0.9 -0.5 -1.8 -0.2 -1.8 -0.8
1953 -1.2 0.6 0.5 -2.7 -1.2 1.5 2.2 2.1 1.4 1.6 2.1 0.9
1954 0.3 1.6 0.7 0.9 -1.6 1.1 3.3 0.0 2.4 1.0 2.1 1.6
1955 -2.0 -2.2 -2.6 0.8 0.0 -0.2 1.4 1.3 3.7 -1.3 -3.1 -0.8
1956 -0.8 -2.2 0.6 -1.6 4.9 1.0 -0.8 -1.2 -0.7 0.9 1.7 1.7
1957 1.8 -1.0 -1.7 1.0 0.3 -3.1 -1.6 0.8 -1.9 2.5 -1.9 1.3
1958 -0.6 -2.4 -2.5 1.5 -0.6 -2.0 -2.1 -0.5 -1.3 1.6 1.7 -1.0
1959 -3.0 1.6 1.7 0.8 -0.4 1.4 1.9 -0.2 -0.2 1.5 1.2 2.0
1960 -2.0 -3.3 -0.8 1.5 0.0 0.6 2.0 -3.5 1.4 -2.9 0.5 2.1
1961 0.9 1.0 0.3 -1.3 -1.2 3.5 0.3 1.3 2.1 1.8 -0.2 -4.5
1962 2.1 0.9 -4.2 0.4 -0.3 -0.4 -2.4 0.9 -0.6 0.0 -0.4 -1.2
1963 -5.1 -1.2 0.9 -0.9 5.2 -1.8 -2.3 0.3 2.0 2.1 -1.2 -2.5
1964 -1.5 -1.5 -1.3 1.2 1.6 -0.3 1.6 -3.0 -0.9 1.2 0.5 0.0
1965 -0.2 -3.7 -1.2 3.0 -0.7 1.1 -0.9 0.6 -0.2 -0.6 -1.9 0.7
1966 -3.5 -2.5 0.4 -1.1 2.3 0.9 0.8 -2.9 -1.2 -3.4 0.7 1.8
1967 -1.6 1.4 2.4 0.7 -0.4 2.1 -0.5 0.2 0.1 2.0 1.0 -0.9
1968 0.5 -1.7 1.7 -1.9 -0.8 0.3 -3.6 -1.1 -1.0 -3.1 -1.7 -1.4
1969 -3.3 -3.2 -2.6 1.5 -1.3 0.0 1.2 -0.6 1.8 0.5 -0.6 1.3
1970 -2.9 1.1 -1.3 0.9 2.0 0.6 -0.5 -0.6 0.3 -0.6 0.0 -1.5
1971 -1.2 1.0 0.2 -1.8 2.4 -1.9 -1.9 2.2 -1.8 -0.4 1.1 0.8
1972 0.4 0.6 1.1 1.2 2.7 3.1 -0.8 0.1 -3.1 -1.4 1.3 1.7
1973 0.5 2.3 0.9 -3.3 -0.8 1.9 0.5 0.8 -0.3 -1.1 -1.2 0.0
1974 2.2 1.1 0.3 -0.4 -0.3 -1.0 1.1 0.0 1.0 -0.1 0.8 1.8
1975 1.3 -0.6 -0.3 0.1 -1.0 -0.9 -0.7 -0.4 2.0 -1.0 1.2 -0.6
1976 0.7 1.2 2.3 0.4 2.6 0.7 -3.0 -2.6 -4.6 1.6 1.2 -2.6
1977 -1.7 -1.0 -0.5 0.6 -0.4 -1.5 0.5 -0.5 -0.9 0.7 -0.7 -1.6
1978 1.6 -3.1 2.9 -1.9 1.5 1.2 -2.3 -2.1 0.2 -0.2 2.7 -3.1
1979 -2.6 -1.0 1.2 -1.5 -0.1 0.6 0.5 0.0 0.4 0.2 1.3 1.3
1980 -1.7 0.5 0.0 -0.2 -2.1 1.3 -1.6 -2.1 1.6 -1.3 -2.7 1.5
1981 1.0 1.2 -1.1 -1.2 0.1 -1.8 1.6 0.4 -0.3 0.3 -0.8 -1.6
1982 -1.3 1.7 2.5 -0.6 1.0 -3.0 -0.8 2.5 0.5 1.1 2.2 2.6
1983 2.6 -1.1 2.0 -1.2 -0.4 0.6 -0.5 1.4 -1.9 2.0 -3.6 0.3
1984 3.4 1.6 -1.9 -1.0 1.6 0.3 -1.7 0.5 0.4 1.3 0.3 1.5
1985 -2.7 -1.5 0.6 0.2 -0.9 -1.9 0.3 1.2 -1.7 -0.4 -2.4 -1.2
1986 2.4 -2.7 3.9 0.0 2.4 0.6 0.6 -3.7 -3.3 3.6 3.3 1.9
1987 -3.5 -0.7 -0.1 0.6 -1.8 -1.1 0.0 -3.3 -0.4 0.8 0.1 -2.3
1988 1.1 0.3 0.9 -2.4 -0.4 0.2 0.8 1.5 0.6 -1.6 -2.2 0.5
1989 2.4 3.2 3.2 0.8 0.3 -1.2 -0.6 2.4 -0.4 0.9 -1.4 -3.4
1990 3.0 3.2 2.3 3.1 -2.0 1.0 -0.1 0.9 -0.7 0.5 -1.1 1.1
1991 0.7 0.5 -0.1 1.1 1.0 -0.9 -1.4 1.6 -0.5 -0.3 1.6 0.2
1992 -1.0 2.0 2.0 1.8 0.3 -0.2 -0.2 2.3 -0.5 -1.2 2.2 1.2
1993 2.1 0.3 1.2 1.5 -3.6 -0.3 -0.2 -0.2 -2.6 -0.7 2.5 2.6
1994 2.0 -0.4 4.4 1.1 -0.5 2.1 0.7 -1.0 -0.1 -1.2 0.2 1.6
1995 1.4 2.3 1.8 -1.9 -0.8 -2.1 -1.4 -0.8 0.6 -0.3 -3.0 -3.8
1996 -1.8 0.9 -2.6 -1.0 -1.8 0.7 1.2 0.6 -0.6 1.6 1.0 -3.7
1997 -2.4 3.7 1.2 -1.8 -1.9 -3.1 1.1 0.7 -0.8 -2.6 0.1 -0.5
1998 -0.7 0.7 0.5 0.7 -0.2 -1.0 0.3 1.5 -2.0 1.0 0.9 1.6
1999 1.3 2.2 0.2 0.0 0.4 1.2 -1.8 -2.6 0.9 0.4 0.8 1.7
2000 0.1 3.1 0.4 -2.5 1.4 -0.5 -2.9 0.4 0.2 4.5 0.0 -2.2
2001 -0.1 -0.5 -1.5 1.4 -1.0 -1.9 0.3 0.6 -2.8 0.9 1.4 -4.1
2002 0.5 1.7 0.9 2.2 1.9 1.9 1.6 0.6 -4.4 -2.0 1.3 -2.4
2003 0.4 1.2 0.5 -99. -99. -99. -99. -99. -99. -99. -99. -99.
Return to Climate Indices Table
Seasonal Station Based NAO Index
Seasonal index of the NAO based on the difference of normalized sea level pressures (SLP) between Ponta Delgada, Azores and Stykkisholmur/Reykjavik, Iceland since 1865. (Missing Value = -99.)
DJF JFM FMA MAM AMJ MJJ JJA JAS ASO SON OND NDJ
1865 -1.5 -0.9 -0.8 -0.1 -0.4 -0.1 0.9 2.0 0.2 -1.0 -0.9 0.3
1866 1.1 0.5 -0.6 -2.4 -2.2 -1.0 0.2 1.1 0.9 0.5 -0.3 -2.3
1867 -1.2 -3.3 -1.0 -4.0 -1.0 -3.5 0.0 0.8 2.9 -0.6 -0.9 -1.2
1868 2.1 3.7 4.7 4.5 3.9 3.4 2.8 -0.7 1.5 -0.4 0.5 -0.3
1869 2.0 2.1 1.7 -1.0 -2.6 -2.8 -1.7 -0.8 -1.5 0.0 0.0 0.9
1870 -1.4 -2.2 -2.6 -0.3 1.6 1.4 -1.3 -1.3 -0.7 -0.8 -2.4 -1.2
1871 -0.4 1.3 -0.7 -1.3 -3.0 -1.0 -0.1 -0.9 -0.9 -2.9 -0.9 -0.2
1872 0.6 -0.3 -1.3 -0.7 0.3 -0.3 -2.1 -3.3 -0.8 0.5 0.6 0.8
1873 0.2 1.0 -1.0 -1.2 -1.9 0.4 2.6 0.1 1.3 -1.2 0.2 0.4
1874 1.6 1.7 1.8 1.1 0.6 -0.4 0.9 1.7 2.3 1.5 0.7 -0.5
1875 -1.0 -1.3 -1.8 -0.5 1.6 2.7 0.5 -2.2 -1.2 -2.7 -1.9 -1.2
1876 -0.2 0.3 -0.3 0.4 1.7 3.2 3.0 -1.2 -3.0 -5.9 -4.3 -2.6
1877 0.2 1.1 -0.4 -2.7 -3.8 -1.2 -2.2 -4.0 -3.7 0.1 2.6 2.6
1878 1.2 0.2 -1.1 -1.5 -3.0 -1.0 -2.2 -0.9 -1.8 -2.5 -5.4 -4.7
1879 -2.4 0.6 1.2 1.5 0.1 0.1 -1.3 1.3 1.0 -1.6 -2.9 -2.9
1880 -0.4 0.4 1.4 0.8 0.5 -2.0 -1.9 -2.4 -3.9 -2.6 -2.9 -4.4
1881 -4.7 -4.7 -2.7 -2.4 -0.3 2.0 1.0 -0.9 -2.0 -0.6 1.9 2.7
1882 2.1 2.5 2.0 1.5 -1.5 0.0 1.2 2.1 1.2 2.0 0.2 0.5
1883 1.2 0.7 0.8 -0.6 0.5 -1.5 -1.8 -0.9 1.8 2.5 2.5 1.6
1884 1.1 1.4 0.4 0.0 -0.8 -0.6 -0.3 0.0 2.0 0.7 1.2 0.3
1885 -0.4 -0.7 -0.2 0.7 0.8 0.1 -1.3 -1.0 -1.2 -0.2 -1.5 -1.0
1886 -0.5 -0.4 -1.1 -1.8 -1.2 0.0 2.3 1.1 1.1 1.0 1.0 1.6
1887 1.4 0.6 -1.7 -2.9 -2.9 -0.9 -2.4 -1.7 -3.5 -3.1 -3.6 -2.8
1888 -3.0 -2.4 -2.2 -2.1 -2.1 -2.6 -2.0 -2.7 -3.6 -1.6 0.6 2.5
1889 1.5 0.6 0.8 1.1 2.4 -0.1 0.3 -1.5 0.6 1.2 3.1 3.8
1890 2.3 1.8 1.4 2.2 1.7 1.1 2.0 1.9 1.1 2.5 0.9 1.0
1891 0.2 0.0 -0.7 -2.0 -3.5 -3.8 -3.3 0.0 1.7 1.4 1.5 1.2
1892 0.0 -1.4 -2.2 -2.3 -2.4 -2.3 -1.1 1.2 -1.1 -0.4 -1.8 -1.7
1893 -1.3 -0.9 0.2 -0.9 -2.1 -2.1 -2.8 -0.4 -0.1 -0.6 0.3 0.5
1894 3.1 2.8 3.7 1.8 2.1 1.5 2.2 -1.8 -3.9 -2.1 0.1 0.2
1895 -3.5 -3.2 -3.0 0.6 -0.4 0.2 -0.4 0.0 -2.0 -2.1 -1.8 -1.1
1896 -0.2 1.2 3.0 3.7 2.1 1.4 0.7 1.0 -1.7 -2.1 -0.5 -0.4
1897 0.6 0.3 2.7 2.6 1.2 -1.7 -1.2 0.8 -0.5 -1.2 -0.9 0.8
1898 1.6 1.1 1.3 0.3 0.2 -2.1 -0.9 -0.5 -0.5 -0.3 0.4 -0.2
1899 -1.5 -2.5 -2.4 -2.3 -0.2 0.8 0.5 0.5 -1.7 -0.3 -1.1 1.0
1900 -1.2 -1.7 -2.9 -0.8 0.6 -0.4 -0.6 1.2 1.1 2.4 1.7 1.6
1901 -1.1 -1.9 -1.8 -0.5 0.7 0.4 2.0 1.8 2.4 0.1 -0.3 -1.2
1902 -1.8 -1.4 -2.2 -0.1 -2.8 -2.8 -4.2 -3.2 -1.4 -0.7 0.5 0.3
1903 1.3 2.8 3.1 3.1 -1.2 -1.4 -1.9 -0.2 -0.6 -0.2 0.3 1.8
1904 1.7 1.7 2.5 2.9 2.9 -0.5 -2.0 -0.9 -0.1 0.2 -0.9 -0.6
1905 0.5 1.7 1.2 0.9 -0.7 0.8 0.2 1.3 -0.5 0.1 -0.6 1.4
1906 2.0 1.8 2.0 -0.2 -0.6 -1.4 -0.5 1.1 0.8 1.4 1.5 1.3
1907 2.0 2.8 3.5 2.1 -0.1 -2.5 -1.0 -1.4 -0.1 1.4 1.4 1.8
1908 2.0 2.7 2.3 1.7 0.4 1.1 0.2 -0.2 -0.6 -0.3 0.7 1.9
1909 1.5 -0.2 -0.9 -2.0 -1.3 -0.4 2.1 1.6 1.6 -0.7 -1.4 -0.8
1910 2.0 3.7 2.8 1.8 0.9 1.5 -0.8 -1.7 -1.7 -2.4 -1.7 -0.6
1911 0.7 0.9 0.4 1.1 1.3 1.2 -1.3 -1.3 -0.9 -0.1 0.4 -0.1
1912 -1.6 -1.0 -0.1 2.3 1.2 0.0 -1.1 -2.5 -0.7 0.6 2.3 1.7
1913 1.3 1.9 2.9 4.2 3.4 1.3 0.9 -1.0 -1.7 0.6 1.2 1.4
1914 0.6 1.2 2.2 2.8 3.6 2.7 1.4 -0.1 -0.1 -0.3 0.6 1.2
1915 1.6 -0.6 0.0 -1.9 -0.5 -3.0 -2.7 -2.5 -1.1 -2.0 -2.4 -1.4
1916 1.1 0.7 0.0 -1.9 -0.4 -1.1 -1.7 -1.3 0.4 0.8 -1.2 -3.4
1917 -3.5 -2.1 -2.0 -2.8 -3.1 -2.3 -0.8 0.0 1.9 3.1 0.7 -2.9
1918 -1.8 -0.6 1.9 0.5 0.7 -0.3 0.1 -0.3 2.2 1.8 1.4 0.5
1919 -1.3 -1.6 -1.6 0.0 1.9 0.7 1.6 0.3 0.0 -1.4 0.0 1.9
1920 2.9 3.4 2.0 2.6 -0.2 2.6 0.8 1.7 0.2 1.9 0.0 1.0
1921 0.2 2.4 1.7 3.2 0.7 0.7 -0.7 -0.2 -0.5 -1.2 0.7 1.5
1922 3.0 2.0 2.0 0.9 2.2 3.3 3.3 2.5 -1.1 -1.7 -1.3 1.3
1923 1.7 1.2 0.8 0.0 0.3 1.0 1.7 2.3 1.9 1.8 1.4 0.9
1924 0.3 -1.8 -3.4 -3.9 -1.7 0.5 1.6 2.4 1.8 1.4 2.3 2.3
1925 3.0 1.1 1.5 1.1 3.0 2.9 2.4 1.7 -0.7 -2.2 -4.0 -2.7
1926 -1.5 0.5 0.7 0.0 -1.0 -1.4 -0.2 0.2 -2.1 -0.6 -0.7 1.7
1927 0.8 2.0 1.6 1.0 -0.7 -1.6 -0.1 -0.1 -2.1 -1.6 -3.1 0.4
1928 1.1 2.0 0.8 -1.6 -2.6 -3.1 -1.9 -0.9 0.2 1.9 2.1 -1.5
1929 -2.2 -3.0 -2.1 -1.6 -1.1 0.9 -0.4 0.8 2.0 3.0 3.3 3.0
1930 1.8 0.1 -0.8 0.1 2.5 2.9 1.4 -1.9 -1.0 -0.2 2.0 1.5
1931 2.0 -0.7 -0.3 -2.3 -0.5 -0.6 -1.1 -0.9 -2.1 0.4 0.9 1.8
1932 -1.4 -2.0 -2.7 -1.2 -0.9 -0.9 0.8 1.7 1.9 1.6 1.1 1.2
1933 -0.3 0.0 -1.7 -0.3 -0.1 2.3 3.1 1.6 -0.9 -1.2 -1.1 0.9
1934 1.0 2.2 0.9 1.7 -0.9 0.8 0.2 2.7 2.6 1.2 -0.5 -0.8
1935 0.7 1.2 0.8 -1.6 -1.9 1.0 3.2 2.9 3.3 3.5 1.5 -2.0
1936 -3.9 -3.5 -2.6 -0.9 0.1 1.2 1.8 0.1 1.3 1.8 2.8 1.9
1937 0.9 -0.5 -0.7 -0.3 1.3 0.8 0.4 1.6 0.8 -1.9 -2.5 -0.6
1938 0.2 1.8 0.0 1.2 -0.2 2.3 2.3 2.5 3.8 4.4 3.2 0.0
1939 0.5 0.4 1.7 0.4 -0.3 -0.3 0.1 -2.1 -1.9 -1.0 -0.5 -1.8
1940 -3.4 -3.2 -2.5 -1.4 0.4 0.9 1.5 0.5 0.2 1.0 0.6 -1.2
1941 -2.2 -2.5 -1.7 -1.4 -0.8 1.1 1.0 0.2 -1.3 -1.3 -0.1 1.4
1942 -0.3 -1.6 -3.1 -1.7 -1.3 -0.5 0.5 2.8 2.4 0.5 -0.2 -1.0
1943 1.3 1.5 3.5 2.5 3.0 0.9 -0.2 0.9 1.2 2.7 1.8 2.0
1944 1.0 -0.4 -1.3 -1.3 -0.1 -1.0 -0.7 0.2 2.5 2.0 1.8 -0.5
1945 0.8 0.5 1.2 -0.7 -1.6 0.2 1.0 1.1 -0.5 -3.0 -3.6 -1.5
1946 -0.2 0.7 1.1 0.7 2.0 0.9 3.5 2.8 -0.4 -1.6 -0.8 0.3
1947 -1.8 -3.7 -3.1 -0.5 2.2 0.2 0.2 1.6 0.9 -0.3 -2.3 -1.5
1948 -0.8 1.1 1.5 2.2 0.8 -0.7 -0.6 -0.3 1.0 -0.2 -0.5 -0.5
1949 1.3 1.4 2.1 1.1 0.8 -1.4 -1.9 -1.5 -0.8 0.8 1.1 1.0
1950 1.0 0.8 1.6 0.0 -0.1 -1.4 0.7 2.5 2.8 1.6 -0.3 -0.1
1951 0.9 0.3 -0.9 -3.1 -3.5 -2.7 -0.5 1.1 2.0 0.9 2.0 2.5
1952 1.5 -0.6 -1.2 -1.3 0.3 -1.0 0.0 -1.1 -1.3 -2.2 -1.5 -2.0
1953 -0.7 0.0 -0.3 -1.4 -1.8 0.9 2.8 2.8 2.6 3.0 2.4 1.7
1954 1.5 1.3 1.8 0.3 0.4 1.0 2.0 2.7 1.8 3.0 2.5 0.5
1955 -1.7 -3.4 -2.6 -1.5 0.4 0.5 1.2 3.5 1.4 -1.4 -2.7 -2.3
1956 -2.0 -1.3 -1.7 1.6 2.0 3.1 -0.5 -1.4 -0.2 1.4 2.2 2.8
1957 1.2 -0.4 -1.3 -0.7 -0.5 -2.3 -2.2 -1.6 1.1 -0.7 0.9 -0.6
1958 -1.1 -2.8 -2.4 -1.4 -0.2 -2.4 -2.4 -2.0 0.3 1.7 1.1 -1.6
1959 -1.2 0.0 2.3 1.5 1.0 1.3 1.5 0.6 0.9 1.6 2.4 0.3
1960 -2.2 -3.2 -2.1 0.2 1.3 1.1 -0.6 0.0 -2.6 -0.8 0.2 1.9
1961 2.0 1.1 0.3 -0.9 0.0 1.2 2.7 2.1 2.8 1.8 -1.9 -1.0
1962 -0.2 -0.4 -1.6 -3.1 0.0 -1.4 -0.9 -1.0 0.1 -0.5 -0.9 -3.9
1963 -4.0 -2.9 -0.7 2.3 1.3 1.3 -1.9 0.4 2.5 1.2 -1.1 -2.8
1964 -2.8 -2.2 -1.3 0.3 1.6 1.7 -0.8 -1.2 -0.8 0.7 0.8 0.1
1965 -2.2 -2.7 -1.9 0.4 2.3 -0.3 0.5 -0.3 -0.3 -1.7 -0.9 -2.7
1966 -3.1 -3.0 -1.9 0.7 0.9 2.2 -0.6 -1.9 -4.0 -2.0 -0.1 0.3
1967 0.8 1.0 2.5 1.9 1.2 0.7 1.1 0.0 1.5 2.0 0.9 0.3
1968 -1.1 0.1 -0.9 0.0 -1.6 -2.0 -2.1 -2.8 -3.0 -3.6 -3.1 -3.6
1969 -4.3 -4.7 -3.0 -1.7 0.4 -0.2 0.3 1.4 1.0 0.7 0.7 -1.4
1970 -0.3 -1.5 0.4 0.4 2.0 1.4 -0.1 -0.2 -0.5 -0.2 -1.1 -1.5
1971 -0.8 0.0 0.1 0.2 -0.9 -0.4 -0.9 -0.9 -0.3 -0.2 0.9 1.2
1972 0.9 1.1 1.5 2.6 3.9 3.1 1.6 -2.1 -2.4 -1.3 1.0 1.7
1973 2.4 1.9 0.8 -1.4 -1.8 0.7 1.7 0.4 -0.6 -1.6 -1.1 0.8
1974 1.9 2.0 0.8 0.0 -0.8 -0.2 -0.1 1.0 0.3 0.9 1.4 2.1
1975 1.2 0.2 -0.5 -0.6 -0.8 -1.3 -0.9 0.8 0.1 1.1 -0.1 0.7
1976 0.8 2.1 2.2 3.0 2.1 0.8 -2.1 -5.3 -2.2 -0.3 -0.2 -1.8
1977 -2.7 -1.7 -0.7 -0.2 -0.5 -0.9 -1.0 -0.6 -0.1 -0.4 -0.9 -0.1
1978 -1.6 0.5 -1.1 1.8 0.1 0.6 -1.4 -1.9 -0.8 1.8 -0.5 -2.0
1979 -3.4 -1.3 -0.5 0.1 -0.8 0.5 0.6 0.5 0.4 1.2 1.6 0.2
1980 0.0 -0.6 0.2 -1.0 -0.8 -1.4 -1.1 -0.8 -1.0 -2.0 -1.1 0.2
1981 1.9 0.6 -0.3 -1.4 -1.6 -0.3 -0.1 0.8 0.2 -0.5 -1.2 -2.0
1982 -0.5 1.4 2.2 1.9 -1.4 -1.3 -0.8 1.2 2.0 2.4 3.2 4.0
1983 1.9 1.7 -0.1 0.7 -0.7 -0.1 0.9 -0.6 1.0 -2.1 -0.8 0.6
1984 2.9 1.7 -0.5 -1.3 0.2 0.5 -0.3 -0.3 1.3 1.2 1.6 -0.8
1985 -1.7 -2.0 -0.6 0.2 -1.3 -1.4 -0.3 -0.3 -0.6 -2.7 -2.1 -0.1
1986 -0.7 1.5 0.4 3.9 1.7 2.1 -1.2 -3.5 -0.6 3.0 4.4 0.3
1987 -1.4 -2.2 -0.3 -0.5 -1.2 -1.8 -2.3 -1.6 -0.8 0.4 -0.9 -0.4
1988 -0.2 1.1 -0.2 -0.7 -1.7 0.3 1.4 1.5 -0.2 -2.2 -1.6 0.8
1989 3.4 4.5 4.2 2.9 0.2 -0.7 0.3 0.8 1.4 -0.6 -2.3 -0.5
1990 1.9 4.4 4.5 2.5 1.6 -0.7 1.0 0.1 0.3 -0.8 0.3 0.5
1991 1.2 0.6 0.7 0.8 0.9 -0.4 -0.3 -0.1 0.2 0.7 0.8 0.2
1992 0.7 1.5 3.2 2.5 1.3 0.1 1.0 0.9 -0.1 0.6 1.3 2.9
1993 1.9 1.8 1.4 0.1 -1.1 -2.5 -0.4 -1.9 -1.9 0.1 2.5 3.7
1994 2.0 2.9 2.6 3.6 1.5 1.3 1.2 -0.2 -1.3 -0.7 0.5 1.8
1995 2.8 2.9 1.8 0.1 -2.7 -2.1 -2.1 -0.7 -0.3 -2.0 -3.9 -4.4
1996 -2.1 -1.6 -1.3 -3.2 -1.4 -0.2 1.2 0.5 1.1 1.5 -0.9 -2.9
1997 -0.8 1.3 2.4 -0.8 -3.7 -2.4 -0.9 0.4 -1.8 -1.9 -1.4 -0.7
1998 -0.2 0.2 1.0 0.6 -0.1 -0.6 0.3 -0.4 0.3 0.4 1.8 2.0
1999 2.7 2.0 1.6 0.4 0.9 0.2 -1.3 -1.3 -0.2 1.2 1.6 1.4
2000 2.6 1.9 1.3 -0.4 -1.2 -0.6 -1.4 -0.9 3.3 2.8 0.8 -1.2
2001 -1.3 -1.1 -0.6 -0.8 -0.4 -1.5 -0.6 -1.2 -0.5 0.4 -1.2 -1.1
2002 -0.5 1.6 2.5 2.5 3.5 2.9 2.1 -1.6 -3.2 -2.3 -1.7 -0.4
2003 -0.2 1.1 0.7 -99. -99. -99. -99. -99. -99. -99. -99. -99.
Return to Climate Indices Table
Annual Station Based NAO Index
Annual index of the NAO based on the difference of normalized sea level pressures (SLP) between Ponta Delgada, Azores and Stykkisholmur/Reykjavik, Iceland since 1865. (Missing Value = -99.)
00 01 02 03 04 05 06 07 08 09
1860 -99. -99. -99. -99. -99. -0.66 -0.20 -3.04 4.14 0.42
1870 -2.77 -0.85 -0.83 0.17 2.32 -2.10 -1.85 -0.24 -4.03 -0.69
1880 -1.86 -2.84 2.06 1.73 1.38 -1.40 0.20 -3.05 -2.94 2.57
1890 2.97 -0.34 -2.49 -1.32 2.28 -3.41 1.58 0.38 0.95 -2.40
1900 0.22 -0.78 -2.61 1.69 1.46 1.12 2.29 2.36 2.51 -0.87
1910 1.62 0.99 0.11 2.85 2.40 -2.66 -0.60 -2.21 0.45 -0.47
1920 2.97 2.32 2.21 2.43 -0.02 0.18 -0.31 -0.49 1.43 -0.51
1930 1.46 -0.48 -0.60 -0.21 1.91 1.90 -1.00 -0.81 3.75 -0.66
1940 -1.78 -2.10 -0.84 3.31 0.71 -1.69 1.62 -2.73 0.68 1.53
1950 1.10 0.49 -1.54 1.50 3.26 -2.79 0.54 -0.51 -2.12 1.83
1960 -1.88 0.47 -1.05 -2.16 -1.04 -1.77 -2.54 1.67 -2.97 -2.58
1970 -1.08 -0.08 2.05 0.27 2.18 0.01 0.59 -2.08 -0.42 -0.23
1980 -1.58 -0.55 2.63 0.38 2.17 -3.09 3.14 -3.01 -0.13 2.38
1990 3.88 1.14 2.54 1.71 2.86 -1.11 -2.00 -0.93 1.03 2.25
2000 1.18 -1.91 1.00 -99. -99. -99. -99. -99. -99. -99.
Return to Climate Indices Table
Winter (Dec-Mar) PC Based NAO Index
The normalized DJFM PC values are given in the table below. (Missing Value = -99.) Note: The NAO PC index value for year N refers to an average of December year N-1 and January, February, and March year N. (Example: The 1920 value contains the average of December 1919 and January, February, and March 1920.)
00 01 02 03 04 05 06 07 08 09
1890 -99. -99. -99. -99. -99. -99. -99. -99. -99. -0.65
1900 -1.34 -0.32 -0.66 1.37 -0.03 0.85 0.86 1.10 0.54 -0.50
1910 0.43 0.48 -0.42 1.41 0.51 -0.69 -0.21 -1.16 0.07 -0.86
1920 1.57 0.71 0.59 0.36 -0.62 1.09 -0.27 0.49 0.16 -0.57
1930 0.43 -0.68 -0.03 -0.08 0.97 0.09 -1.93 -0.14 0.57 -0.13
1940 -2.00 -1.25 -1.11 0.67 0.64 -0.12 -0.30 -1.96 0.32 1.12
1950 0.50 -1.00 -0.12 0.01 0.17 -1.23 -1.05 0.07 -1.27 0.14
1960 -1.90 0.79 -0.92 -1.31 -0.81 -0.77 -1.63 0.66 -0.11 -2.65
1970 -1.21 -0.68 0.14 1.28 0.39 0.84 1.34 -1.41 -0.57 -1.48
1980 -0.35 0.34 -0.21 1.40 0.41 -0.85 -0.04 -0.68 -0.18 2.61
1990 2.09 0.61 1.93 1.91 0.86 1.37 -1.47 0.78 0.02 0.67
2000 1.72 -1.04 0.71 0.09 -0.10 0.45 -0.93 1.24 1.13 -99.
Return to Climate Indices Table
DJF PC Based NAO Index
The normalized PC values are given in the table below.(Missing Value = -99.)
00 01 02 03 04 05 06 07 08 09
1890 -99. -99. -99. -99. -99. -99. -99. -99. -99. -0.53
1900 -1.25 -0.22 -0.72 0.99 -0.08 0.81 0.85 0.82 0.49 0.18
1910 0.20 0.49 -0.87 0.71 0.52 -0.27 0.39 -1.26 0.02 -0.97
1920 1.11 0.12 0.52 0.41 -0.03 1.36 -0.61 0.38 0.41 -0.87
1930 0.54 -0.08 0.47 -0.02 0.99 0.13 -2.01 0.40 0.09 -0.25
1940 -1.99 -1.18 -0.77 0.53 0.93 -0.43 -0.32 -1.90 -0.41 1.44
1950 0.34 -0.54 0.69 -0.25 0.31 -1.00 -1.31 0.62 -0.50 -0.15
1960 -1.72 0.47 0.08 -1.64 -0.59 -0.62 -2.05 -0.02 -0.60 -2.45
1970 -1.16 -0.46 -0.01 1.23 0.50 1.12 1.29 -1.77 -1.13 -2.08
1980 -0.15 1.06 -0.87 1.49 1.08 -1.01 -0.99 -0.47 -0.24 2.57
1990 1.35 1.02 1.82 1.98 0.19 1.40 -1.37 0.24 -0.19 1.12
2000 1.92 -0.69 0.61 -0.30 -0.34 1.16 -0.41 0.93 1.19 -99.
Return to Climate Indices Table
MAM PC Based NAO Index
The normalized PC values are given in the table below.(Missing Value = -99.)
00 01 02 03 04 05 06 07 08 09
1890 -99. -99. -99. -99. -99. -99. -99. -99. -99. -1.21
1900 -0.37 -0.25 -0.46 1.06 1.32 0.60 0.16 0.32 0.49 -1.74
1910 0.37 0.98 1.34 2.27 1.73 -1.12 -1.45 -1.57 0.55 -0.09
1920 0.99 1.77 0.23 0.06 -2.03 0.32 -0.17 0.38 -0.56 0.08
1930 -0.25 -1.24 -1.17 -0.77 1.01 -1.24 -0.31 -0.73 1.15 0.24
1940 -1.38 -0.71 -0.82 1.97 0.07 0.17 0.38 0.34 1.44 0.55
1950 0.42 -1.91 -1.61 -0.63 -0.36 -0.95 0.91 -1.11 -1.60 0.63
1960 -0.93 -0.22 -1.76 0.42 0.10 -0.46 -0.60 1.32 0.26 -0.98
1970 -0.50 -0.57 0.68 -0.30 0.01 -0.59 1.34 0.25 0.18 -0.30
1980 -0.74 -0.92 1.45 -0.40 -0.70 -0.12 1.65 0.15 -0.86 1.55
1990 2.49 0.10 1.45 -0.03 1.55 -0.77 -1.21 0.49 0.24 -0.46
2000 0.25 -0.75 1.06 0.74 0.93 -1.34 -1.12 1.49 -99. -99.
Return to Climate Indices Table
JJA PC Based NAO Index
The normalized PC values are given in the table below.(Missing Value = -99.)
00 01 02 03 04 05 06 07 08 09
1890 -99. -99. -99. -99. -99. -99. -99. -99. -99. 0.15
1900 -0.75 1.07 -2.32 -2.32 -1.36 -0.15 -0.85 -2.21 -0.22 -0.56
1910 -2.04 -0.70 -1.71 0.43 0.05 -1.72 -0.54 -0.61 -0.74 0.77
1920 0.70 -0.04 0.26 -0.49 -0.21 0.36 -0.40 -0.53 -1.20 -0.75
1930 -0.71 -1.04 -0.01 0.97 -0.52 0.64 0.40 1.34 0.96 0.02
1940 0.49 0.64 0.27 -1.55 -0.16 -0.59 0.66 1.04 -0.84 0.10
1950 -0.43 -0.17 0.33 0.60 -0.43 2.09 -1.02 -0.74 -2.46 0.49
1960 -1.02 1.26 -0.72 -0.78 0.68 -0.11 0.09 1.70 -0.04 0.49
1970 1.21 -0.00 1.35 1.14 -0.24 1.05 1.58 -0.82 0.03 1.06
1980 -1.03 0.97 -0.18 2.23 1.08 -0.57 0.36 -1.13 0.63 1.65
1990 0.61 0.73 0.27 -1.29 2.18 0.95 1.36 0.17 -0.76 1.14
2000 -0.07 -0.07 0.84 -0.31 -0.32 0.73 1.28 -1.12 -99. -99.
Return to Climate Indices Table
SON PC Based NAO Index
The normalized PC values are given in the table below.(Missing Value = -99.)
00 01 02 03 04 05 06 07 08 09
1890 -99. -99. -99. -99. -99. -99. -99. -99. -99. 1.26
1900 0.31 -0.67 -0.83 -0.20 -0.31 -0.48 -0.53 -0.12 -0.57 -0.65
1910 -1.88 0.15 -0.31 0.57 -0.10 -2.69 0.31 1.74 0.55 -1.13
1920 -0.42 -0.91 -1.12 1.77 0.44 -0.40 -0.13 -0.45 0.46 1.45
1930 0.24 -0.12 1.19 -1.29 0.45 1.31 0.68 -0.34 1.98 -1.09
1940 0.58 -1.55 0.48 0.07 0.47 -1.38 -0.55 -0.47 1.09 -0.30
1950 0.95 -0.17 -1.11 1.59 1.89 -0.94 0.66 0.46 -0.29 -0.40
1960 -1.46 0.65 -0.08 1.01 0.12 -1.14 -0.51 1.90 -2.89 1.83
1970 0.28 0.16 0.05 -0.88 0.23 0.48 -0.96 1.22 2.16 0.34
1980 -0.89 -0.39 1.85 0.52 0.37 -0.58 2.26 -0.08 -0.25 0.65
1990 -0.10 0.63 0.43 -1.40 -0.46 -1.20 0.01 -1.06 -1.20 0.54
2000 0.47 0.68 -2.13 -0.10 0.08 -0.02 -0.26 -0.05 -99. -99.
Return to Climate Indices Table
Annual PC Based NAO Index
The normalized PC values are given in the table below.(Missing Value = -99.)
00 01 02 03 04 05 06 07 08 09
1890 -99. -99. -99. -99. -99. -99. -99. -99. -99. -0.59
1900 -0.40 -0.63 -1.26 0.53 0.67 0.78 0.22 0.35 0.63 -1.12
1910 -0.26 0.93 0.25 1.77 1.43 -2.18 -0.40 -0.69 0.27 -0.36
1920 1.25 1.39 0.68 0.72 -0.09 0.27 -0.23 -0.08 0.97 0.19
1930 0.16 -0.60 -0.15 -0.44 0.73 0.06 -0.36 -0.43 1.73 -0.36
1940 -1.41 -1.11 -0.73 1.10 0.21 -1.10 0.53 -1.26 0.81 1.01
1950 0.10 -0.43 -1.50 0.94 0.69 -1.84 -0.07 -0.25 -2.05 0.47
1960 -2.09 0.35 -0.54 -1.15 0.10 -1.11 -1.98 1.26 -1.80 -1.89
1970 -0.91 -0.39 0.98 0.28 0.69 0.68 0.78 -0.81 -0.31 -0.41
1980 -1.09 -0.90 1.53 0.54 0.82 -1.38 1.35 -1.22 0.16 2.42
1990 2.70 1.06 1.79 0.67 1.36 -0.83 -1.15 0.11 -0.34 0.62
2000 0.68 -0.59 0.29 0.35 0.13 -0.69 -0.26 0.66 -99. -99.
Return to Climate Indices Table
DJFM PC Based NAM Index
The normalized PC values of the DJFM 20-90N SLP EOF1 are given in the table below. (Missing Value = -99.)
00 01 02 03 04 05 06 07 08 09
1890 -99. -99. -99. -99. -99. -99. -99. -99. -99. -0.29
1900 -1.98 0.13 -0.51 1.69 -0.23 0.82 0.38 0.79 0.01 -0.79
1910 0.23 0.49 -0.57 1.26 1.03 -0.98 -0.10 -0.83 0.08 -0.94
1920 1.28 0.55 0.32 0.50 -0.84 0.86 -0.18 0.14 0.16 -0.82
1930 0.48 -1.24 0.52 -0.51 0.74 0.50 -2.44 0.01 0.52 -0.18
1940 -1.63 -0.97 -0.74 0.74 0.56 -0.82 -0.41 -2.11 0.74 1.34
1950 0.35 -1.09 -0.02 -0.05 0.26 -1.13 -1.01 -0.14 -0.84 0.50
1960 -1.54 0.41 -0.32 -0.61 -0.29 -0.78 -1.08 0.25 0.12 -2.64
1970 -1.74 -0.63 0.10 1.34 -0.32 0.87 0.99 -1.83 -0.37 -0.92
1980 -0.68 0.02 0.21 0.91 -0.32 -1.06 -0.45 -0.62 -0.29 2.85
1990 2.08 0.48 1.88 2.16 0.69 1.19 -1.06 1.33 0.23 0.67
2000 1.59 -0.65 1.40 0.43 0.26 0.09 -0.82 1.61 1.28 -99.
Return to Climate Indices Table
Monthly North Pacific Index
Monthly NP values (-1000 mb) Jan 1899 - Apr 2008 (Missing Value = -99.)
J F M A M J J A S O N D
1899 9.9 9.3 9.8 14.8 14.6 16.8 17.8 18.0 13.9 14.5 2.7 7.4
1900 6.6 6.3 5.1 13.1 12.5 12.5 15.9 16.5 14.9 13.8 12.1 4.3
1901 8.9 12.1 12.5 21.2 16.5 14.5 16.5 16.7 13.5 11.8 10.3 9.1
1902 6.0 5.1 16.9 15.1 15.5 13.9 16.8 15.8 15.3 13.1 12.1 15.6
1903 10.2 11.6 18.0 19.1 15.0 12.9 18.3 16.4 15.8 14.1 10.6 9.2
1904 11.9 16.9 17.0 15.7 14.7 17.4 16.7 19.0 16.2 14.5 9.5 9.6
1905 8.9 5.8 8.6 11.1 16.1 16.7 17.9 15.4 15.7 15.1 9.1 7.6
1906 13.7 8.5 12.5 13.0 16.0 14.0 17.3 13.1 14.6 10.6 11.8 14.4
1907 14.6 10.3 19.5 15.7 14.2 15.1 17.1 17.8 16.9 14.0 12.3 7.1
1908 8.6 11.7 19.4 15.9 15.2 16.4 16.3 17.3 15.6 11.8 6.5 7.4
1909 14.3 10.0 14.8 18.5 15.1 15.7 17.3 16.3 14.9 11.6 14.6 13.0
1910 15.6 7.9 8.3 14.2 13.1 16.2 17.9 18.6 15.2 12.9 11.0 8.6
1911 18.4 10.9 14.9 16.9 14.8 14.0 18.2 19.8 16.2 10.3 11.3 9.8
1912 4.7 5.3 16.1 12.8 13.7 15.3 17.3 15.1 13.3 13.8 8.5 8.6
1913 10.4 9.0 10.5 15.2 13.8 13.2 19.0 17.0 13.6 13.4 12.0 3.6
1914 8.9 4.1 16.8 13.6 16.9 14.9 16.5 16.6 16.8 9.9 11.6 11.2
1915 10.1 11.4 8.0 11.0 12.5 19.4 19.3 16.2 15.1 14.2 12.4 10.6
1916 18.0 10.9 12.3 14.6 18.2 16.5 18.2 16.1 15.9 16.6 15.0 8.2
1917 13.0 7.9 16.7 15.0 15.4 18.1 20.1 16.9 15.9 15.1 11.4 6.8
1918 5.1 11.3 17.0 16.9 17.2 15.7 15.5 17.2 14.1 12.2 10.7 8.1
1919 7.9 5.0 11.1 12.0 12.2 16.8 20.2 16.9 15.5 16.2 13.3 7.6
1920 12.0 10.7 16.3 17.8 17.2 13.9 16.5 16.0 14.2 12.3 11.5 7.8
1921 12.3 3.8 13.6 17.1 16.2 12.1 20.5 16.5 15.5 13.5 7.4 10.6
1922 9.2 16.4 11.4 16.9 15.2 16.7 21.5 16.5 16.9 12.3 11.8 3.3
1923 12.4 11.4 15.4 12.2 15.8 14.0 18.0 15.5 14.9 9.0 7.8 10.9
1924 5.6 6.3 11.5 17.7 14.0 16.5 17.7 16.5 13.0 14.6 8.1 7.9
1925 9.4 4.8 11.4 16.1 11.9 15.7 17.5 18.5 14.9 9.7 9.9 5.5
1926 1.4 2.8 6.1 8.8 12.9 13.7 17.5 15.4 14.8 8.0 6.4 8.9
1927 9.2 0.3 15.0 18.1 17.5 13.3 19.4 15.7 11.8 12.4 11.2 10.5
1928 5.8 5.6 9.5 13.5 13.9 15.0 17.2 17.3 16.0 12.4 6.9 4.1
1929 5.5 7.2 14.6 14.6 13.5 13.1 17.9 16.0 12.1 9.4 11.6 11.0
1930 8.4 6.7 16.9 13.0 13.9 14.6 17.2 17.6 16.2 11.2 12.2 4.0
1931 -1.3 6.4 9.8 13.4 14.1 13.7 16.8 16.5 16.2 13.2 12.7 12.1
1932 12.5 12.3 6.2 11.9 14.5 15.5 17.9 17.4 15.1 12.0 12.0 6.4
1933 12.5 11.3 11.2 14.9 16.1 15.7 19.1 15.7 14.3 11.9 12.5 9.8
1934 4.7 -1.4 7.8 13.3 14.1 16.1 19.3 17.7 13.3 12.1 9.2 8.0
1935 5.9 8.2 13.2 15.8 14.6 13.5 17.9 18.1 13.6 15.9 13.5 1.4
1936 3.2 4.9 14.5 13.1 12.8 14.2 17.7 17.7 15.2 9.6 10.4 12.2
1937 17.4 13.4 11.2 15.4 12.4 12.5 17.4 18.1 15.6 8.5 11.2 6.8
1938 8.4 7.2 11.1 9.9 14.1 14.2 18.7 19.4 13.1 8.7 11.7 5.2
1939 7.6 8.8 13.7 15.3 15.4 16.3 17.1 16.2 14.9 13.9 10.0 0.9
1940 -1.3 1.7 7.0 8.6 14.9 14.7 16.2 16.3 12.8 10.7 10.7 3.1
1941 1.0 2.4 9.5 10.1 15.6 12.7 16.0 15.9 14.0 13.2 12.2 6.8
1942 1.2 6.5 13.7 11.9 14.7 15.0 16.5 14.7 13.4 13.3 15.5 12.3
1943 7.8 10.3 15.8 10.2 15.2 15.0 16.4 17.2 13.9 10.6 6.0 6.0
1944 1.8 10.7 14.5 12.3 13.9 15.2 17.6 17.8 16.8 14.3 7.8 -99.
1945 0.4 5.0 11.1 18.4 12.5 16.2 16.2 18.6 14.5 12.9 16.1 4.1
1946 6.7 6.3 13.4 14.6 14.3 15.6 16.5 17.1 14.3 14.2 14.6 13.3
1947 12.8 1.9 10.7 13.0 12.1 14.4 16.9 18.2 16.6 10.5 7.2 9.7
1948 9.1 14.0 16.7 20.7 16.0 15.4 17.2 17.8 15.5 10.8 10.6 14.2
1949 12.0 10.9 6.9 13.5 15.5 16.6 18.8 17.0 13.1 12.4 8.1 10.5
1950 14.9 10.4 8.1 15.5 15.5 15.5 16.2 12.8 12.6 10.8 16.4 8.0
1951 8.3 11.2 15.7 11.9 12.7 14.2 17.9 16.2 12.4 11.5 9.5 13.8
1952 10.4 7.7 14.1 13.7 15.8 14.5 18.4 17.0 14.4 12.4 8.9 3.8
1953 2.5 8.2 14.6 10.4 13.4 17.1 18.2 16.7 15.7 10.5 5.9 8.1
1954 10.8 7.4 16.8 17.5 13.7 13.4 18.2 16.8 15.0 10.7 5.6 11.8
1955 7.1 15.4 16.2 16.6 14.9 15.6 17.0 18.2 16.2 13.1 13.0 11.5
1956 10.2 12.9 14.0 14.2 13.6 15.3 18.8 15.0 13.9 16.2 11.0 7.6
1957 13.8 11.3 7.9 14.9 11.9 12.8 18.6 16.3 11.7 10.7 8.6 12.4
1958 1.0 2.7 14.5 12.5 13.8 14.5 16.4 16.6 14.0 14.6 11.2 5.7
1959 8.4 13.4 12.8 16.1 15.0 14.8 18.4 17.1 12.2 10.4 9.2 10.2
1960 5.9 7.6 13.4 14.8 14.9 16.6 17.0 17.0 16.1 11.9 12.1 5.5
1961 -0.4 6.8 10.3 18.1 15.0 16.4 18.3 15.8 15.8 15.7 12.5 9.8
1962 10.1 7.7 13.3 18.5 18.2 16.8 18.3 17.1 15.6 10.9 8.5 6.7
1963 2.5 2.3 17.4 17.5 15.8 16.3 18.5 16.3 10.7 12.3 11.3 3.2
1964 6.3 10.0 14.6 19.5 20.8 13.8 16.5 16.0 15.0 14.3 12.2 10.7
1965 5.7 10.0 10.9 16.0 16.3 14.2 17.4 15.7 15.0 12.0 13.9 13.3
1966 4.2 12.8 12.2 15.6 16.2 14.0 17.6 16.3 10.3 14.3 15.4 6.7
1967 8.0 8.8 15.8 21.0 18.4 14.4 19.0 14.0 10.2 10.3 12.6 10.0
1968 10.1 0.1 12.3 17.3 16.2 16.2 15.9 15.2 15.9 10.7 6.4 13.6
1969 12.4 8.9 12.9 12.3 12.7 13.2 19.0 16.9 12.2 10.6 10.4 1.8
1970 6.0 2.6 7.9 17.1 16.9 14.6 16.1 16.8 14.3 14.5 14.3 11.9
1971 12.4 7.6 11.2 14.7 14.2 14.5 16.3 15.3 15.3 15.2 11.7 14.2
1972 12.7 10.7 9.8 19.8 14.8 15.5 18.0 14.6 14.8 14.9 9.7 10.7
1973 8.3 8.2 10.6 16.8 14.4 15.1 17.6 17.8 14.3 14.8 14.8 5.3
1974 6.6 11.2 7.4 14.5 15.5 16.0 17.1 14.6 14.4 10.7 10.5 6.1
1975 10.9 8.2 14.4 18.9 14.5 16.6 15.8 17.5 16.5 13.8 12.4 7.0
1976 4.1 13.1 13.8 15.3 14.5 15.8 15.1 15.4 11.8 12.2 7.7 5.1
1977 -1.0 1.2 16.8 16.8 15.6 15.2 17.8 14.0 16.6 11.4 12.5 10.0
1978 0.6 0.6 8.9 14.0 17.6 18.1 17.5 15.2 13.9 12.3 11.2 12.9
1979 6.3 14.2 8.2 15.7 13.4 18.9 16.9 14.2 12.3 8.8 12.5 9.0
1980 6.6 -0.1 10.5 11.3 14.5 18.8 17.1 18.3 14.7 10.5 7.7 5.7
1981 -3.6 5.3 7.0 14.9 13.2 14.9 19.2 15.4 14.5 14.3 8.8 8.2
1982 9.3 11.9 14.8 18.0 16.5 13.3 16.7 17.8 14.8 15.2 9.1 6.0
1983 1.2 -2.3 3.4 16.2 15.5 13.6 17.1 17.8 16.8 14.1 5.0 7.1
1984 6.8 7.5 5.0 15.6 15.5 14.9 18.5 15.7 12.2 12.0 8.0 10.8
1985 0.0 14.2 17.0 17.6 15.6 15.6 17.4 18.1 15.9 15.7 12.5 1.8
1986 1.4 0.5 7.7 18.1 15.3 13.9 17.8 15.4 15.0 11.0 11.9 1.0
1987 3.2 5.5 8.3 12.3 16.5 14.0 15.9 16.6 15.4 12.4 9.7 9.5
1988 5.4 4.2 11.9 13.6 13.5 14.0 17.6 15.6 16.2 11.6 9.8 8.3
1989 12.0 15.0 13.5 16.0 17.4 16.4 18.9 15.9 13.4 14.6 14.0 5.3
1990 7.6 17.5 10.2 15.8 14.4 15.8 16.9 15.1 13.6 14.5 19.1 11.9
1991 7.7 2.7 14.7 14.0 14.5 16.2 16.6 14.9 11.7 13.6 8.4 7.8
1992 -1.1 7.0 10.3 13.9 15.9 13.8 17.3 15.8 15.0 11.7 9.8 13.1
1993 10.8 2.4 7.6 9.7 12.5 15.0 16.9 15.8 15.7 12.5 13.9 6.8
1994 8.3 10.4 12.4 14.0 13.6 16.9 17.2 17.5 13.8 12.7 16.7 5.4
1995 2.2 6.6 11.9 13.9 13.8 14.6 16.8 17.3 10.2 12.9 11.9 -0.3
1996 8.3 8.0 10.9 9.6 15.8 16.7 18.2 18.1 14.6 14.3 12.3 9.8
1997 2.0 4.2 15.0 11.4 12.9 14.8 16.0 16.0 12.5 13.3 10.0 8.4
1998 0.7 0.2 8.1 15.1 15.8 17.7 17.8 18.8 14.5 13.9 9.0 11.4
1999 8.0 6.9 12.0 17.1 15.7 14.0 19.1 14.4 14.3 14.5 11.3 10.5
2000 13.5 0.9 5.9 15.1 16.3 15.4 17.4 18.1 13.4 12.9 9.1 3.2
2001 2.0 9.5 11.6 16.1 15.5 16.5 17.4 16.4 13.7 13.9 6.8 6.7
2002 7.9 10.1 14.5 18.4 14.4 13.7 16.8 16.2 14.5 10.2 4.5 3.3
2003 -0.4 7.5 10.4 14.5 15.9 13.7 18.2 16.4 13.2 11.4 18.1 3.8
2004 5.1 1.8 14.0 11.6 15.2 16.5 15.0 13.9 15.9 12.5 11.1 9.2
2005 4.0 8.1 8.4 14.0 11.9 14.6 17.0 14.9 16.1 13.0 13.9 -0.5
2006 8.0 14.4 14.8 15.5 16.5 16.5 16.3 18.1 14.7 14.2 14.7 4.9
2007 8.5 8.2 12.7 9.9 15.5 16.3 14.7 16.1 13.9 13.3 7.6 10.6
2008 9.3 5.8 13.2 18.2 -99. -99. -99. -99. -99. -99. -99. -99.
Return to Climate Indices Table
NDJFM North Pacific Index
Nov-Mar NP Values (-1000 mb) 1900-2008 (Missing Value = -999.)
00 01 02 03 04 05 06 07 08 09
1900 5.62 10.00 9.48 13.51 13.11 8.48 10.29 14.14 11.82 10.60
1910 11.88 12.78 9.43 9.41 9.07 10.46 12.84 12.16 10.30 8.56
1920 11.98 9.82 11.01 10.86 8.44 8.33 5.14 7.96 8.52 7.67
1930 10.93 6.22 11.15 10.65 6.66 8.91 7.51 12.92 8.94 9.39
1940 3.68 5.35 8.10 12.33 7.80 6.08 9.33 10.67 11.34 10.92
1950 10.39 11.90 11.09 7.60 9.81 11.21 12.30 10.31 7.83 10.30
1960 9.26 6.87 10.68 7.47 9.08 9.89 11.27 10.96 9.02 10.83
1970 5.74 11.48 11.84 9.51 9.06 10.02 10.09 5.95 6.49 10.55
1980 7.69 4.44 10.60 3.46 6.28 10.01 4.79 5.97 8.13 11.74
1990 10.90 11.24 6.45 8.75 10.36 8.56 7.77 8.67 5.48 9.45
2000 8.45 7.08 9.20 5.06 8.56 8.15 10.11 9.83 9.30 -999.
Return to Climate Indices Table
NDJFM North Pacific Anomalies
Mean for 1925-1989 1008.90
Anomalies (Missing Value = -999.)
00 01 02 03 04 05 06 07 08 09
1900 -3.28 1.10 0.58 4.61 4.21 -0.42 1.39 5.24 2.92 1.70
1910 2.98 3.88 0.53 0.51 0.17 1.56 3.94 3.26 1.40 -0.34
1920 3.08 0.92 2.11 1.96 -0.46 -0.57 -3.76 -0.94 -0.38 -1.23
1930 2.03 -2.68 2.25 1.75 -2.24 0.01 -1.39 4.02 0.04 0.49
1940 -5.22 -3.55 -0.80 3.43 -1.10 -2.82 0.43 1.77 2.44 2.02
1950 1.49 3.00 2.19 -1.30 0.91 2.31 3.40 1.41 -1.07 1.40
1960 0.36 -2.03 1.78 -1.43 0.18 0.99 2.37 2.06 0.12 1.93
1970 -3.16 2.58 2.94 0.61 0.16 1.12 1.19 -2.95 -2.41 1.65
1980 -1.21 -4.46 1.70 -5.44 -2.62 1.11 -4.11 -2.93 -0.77 2.84
1990 2.00 2.34 -2.45 -0.15 1.46 -0.34 -1.13 -0.23 -3.42 0.55
2000 -0.45 -1.82 0.30 -3.84 -0.34 -0.75 1.21 0.93 0.40 -999.
Return to Climate Indices Table
Contact Information
Jim Hurrell, Senior Scientist
Phone: 303.497.1383
Email: jhurrell(at)ucar.edu
Facsimile: 303.497.1333
Postal Mail: CAS, CGD/NCAR,
PO Box 3000,
Boulder, CO 80307-3000
Express Mail: CAS, CGD/NCAR,
1850 Table Mesa Drive,
Boulder, Colorado 80305
