Hurrell PC-Based North Atlantic Oscillation Index (JJA)
  1899   -0.14
  1900    0.64
  1901   -1.01
  1902    2.19
  1903    2.10
  1904    1.04
  1905    0.04
  1906    0.70
  1907    1.92
  1908    0.09
  1909    0.15
  1910    1.68
  1911    0.60
  1912    1.41
  1913   -0.65
  1914   -0.33
  1915    1.62
  1916    0.38
  1917    0.53
  1918    0.61
  1919   -0.95
  1920   -0.88
  1921   -0.18
  1922   -0.62
  1923    0.15
  1924    0.01
  1925   -0.56
  1926    0.31
  1927    0.35
  1928    0.93
  1929    0.58
  1930    0.46
  1931    0.90
  1932    0.08
  1933   -1.04
  1934    0.40
  1935   -0.70
  1936   -0.43
  1937   -1.29
  1938   -1.10
  1939    0.07
  1940   -0.58
  1941   -0.73
  1942   -0.25
  1943    1.36
  1944    0.13
  1945    0.44
  1946   -0.96
  1947   -1.04
  1948    0.71
  1949   -0.08
  1950    0.26
  1951    0.20
  1952   -0.36
  1953   -0.75
  1954    0.24
  1955   -1.74
  1956    0.83
  1957    0.72
  1958    2.33
  1959   -0.38
  1960    0.83
  1961   -1.45
  1962    0.62
  1963    0.75
  1964   -0.58
  1965   -0.04
  1966   -0.08
  1967   -1.61
  1968    0.15
  1969   -0.33
  1970   -1.10
  1971    0.00
  1972   -1.22
  1973   -1.01
  1974    0.16
  1975   -0.85
  1976   -1.38
  1977    0.70
  1978   -0.11
  1979   -1.02
  1980    0.94
  1981   -0.81
  1982    0.19
  1983   -2.01
  1984   -0.99
  1985    0.46
  1986   -0.32
  1987    1.11
  1988   -0.72
  1989   -1.53
  1990   -0.64
  1991   -0.73
  1992   -0.26
  1993    1.21
  1994   -2.05
  1995   -0.67
  1996   -1.21
  1997    0.02
  1998    0.66
  1999   -0.93
  2000    0.11
  2001    0.05
  2002   -0.77
  2003    0.30
  2004    0.31
  2005   -0.53
  2006   -1.04
  2007    1.09
  2008    1.28
  2009    2.07
  2010    0.45
  2011    2.11
  2012    1.56
  2013   -1.64
  2014    0.90
  2015    1.64
  2016    0.72
  2017   -0.41
  2018   -1.85
  2019    2.11
  2020    0.30
  2021   -1.04
  2022   -0.38
  2023    1.32
  2024   -1.77
  2025   -1.44