Year,Value,Contiguous U.S. (Lower 48),Temp,Jan,(°F)
1940,21.83
1941,29.945
1942,27.193
1943,28.787
1944,31.74
1945,29.697
1946,29.625
1947,29.415
1948,27.406
1949,26.039
1950,30.352
1951,30.353
1952,32.114
1953,36.494
1954,30.935
1955,29.491
1956,31.153
1957,27.409
1958,31.868
1959,29.574
1960,29.402
1961,29.574
1962,26.932
1963,24.289
1964,31.752
1965,31.85
1966,26.121
1967,33.073
1968,28.86
1969,29.571
1970,27.375
1971,29.412
1972,29.933
1973,29.581
1974,30.956
1975,32.374
1976,30.066
1977,23.583
1978,25.848
1979,22.476
1980,31.3
1981,32.472
1982,26.384
1983,33.16
1984,29.029
1985,26.124
1986,34.649
1987,31.297
1988,27.891
1989,33.899
1990,36.503
1991,29.444
1992,33.378
1993,30.422
1994,29.458
1995,32.993
1996,29.627
1997,29.56
1998,34.7
1999,33.484
2000,33.498
2001,30.813
2002,34.383
2003,32.357
2004,29.833
2005,32.885
2006,39.063
2007,31.123
2008,30.478
2009,30.845
2010,30.353
2011,29.414
2012,36.203
2013,31.785
2014,30.47
2015,32.869
2016,32.292
2017,33.603
2018,32.572
2019,32.367
2020,35.859
2021,34.766
2022,31.044
2023,35.444
2024,32.082
2025,29.463