Year,Value,Contiguous U.S. (Lower 48),Temp,Apr,(°F)
1940,27.102
1941,27.055
1942,32.09
1943,34.59
1944,26.86
1945,34.121
1946,43.503
1947,32.437
1948,44.028
1949,34.098
1950,33.374
1951,30.499
1952,34.251
1953,30.65
1954,48.92
1955,46.159
1956,32.167
1957,35.747
1958,33.164
1959,39.849
1960,43.975
1961,30.266
1962,36.873
1963,39.938
1964,38.72
1965,39.153
1966,34.131
1967,39.215
1968,36.894
1969,40.125
1970,35.854
1971,36.522
1972,37.817
1973,29.414
1974,40.364
1975,30.261
1976,39.712
1977,48.306
1978,39.14
1979,34.928
1980,33.348
1981,51.059
1982,30.658
1983,24.096
1984,30.578
1985,48.709
1986,43.339
1987,42.288
1988,36.027
1989,46.208
1990,38.593
1991,42.488
1992,44.02
1993,32.828
1994,41.769
1995,35.409
1996,36.854
1997,27.721
1998,32.686
1999,37.354
2000,40.313
2001,44.92
2002,46.136
2003,40.213
2004,42.262
2005,42.667
2006,48.292
2007,34.081
2008,37.822
2009,37.897
2010,48.015
2011,43.262
2012,48.159
2013,37.73
2014,41.291
2015,44.427
2016,44.626
2017,47.731
2018,34.755
2019,46.552
2020,37.727
2021,40.984
2022,41.327
2023,43.677
2024,46.162
2025,46.209