"Figure 1. U.S. Annual Heat Wave Index, 1895-2015",
Source: EPA's Climate Change Indicators in the United States: www.epa.gov/climate-indicators,
"Data source: Kunkel, 2016",
Web update: August 2016,
Units: Heat Wave Index,
,
Year,Heat Wave Index
1895,0.025
1896,0.082
1897,0.153
1898,0.057
1899,0.048
1900,0.121
1901,0.309
1902,0.061
1903,0.01
1904,0.006
1905,0.048
1906,0.035
1907,0.02
1908,0.031
1909,0.047
1910,0.062
1911,0.19
1912,0.036
1913,0.089
1914,0.101
1915,0.035
1916,0.121
1917,0.171
1918,0.22
1919,0.03
1920,0.01
1921,0.119
1922,0.019
1923,0.022
1924,0.037
1925,0.149
1926,0.057
1927,0.007
1928,0.058
1929,0.022
1930,0.507
1931,0.545
1932,0.112
1933,0.214
1934,0.852
1935,0.158
1936,1.255
1937,0.055
1938,0.047
1939,0.089
1940,0.214
1941,0.174
1942,0.067
1943,0.067
1944,0.07
1945,0.006
1946,0.01
1947,0.132
1948,0.087
1949,0.069
1950,0.017
1951,0.066
1952,0.185
1953,0.072
1954,0.282
1955,0.128
1956,0.029
1957,0.005
1958,0.024
1959,0.017
1960,0.037
1961,0.043
1962,0.028
1963,0.029
1964,0.04
1965,0.007
1966,0.04
1967,0.004
1968,0.014
1969,0.029
1970,0.019
1971,0.041
1972,0.032
1973,0.022
1974,0.015
1975,0.057
1976,0.048
1977,0.078
1978,0.036
1979,0.021
1980,0.247
1981,0.069
1982,0.009
1983,0.139
1984,0.016
1985,0.03
1986,0.081
1987,0.045
1988,0.291
1989,0.042
1990,0.074
1991,0.039
1992,0.027
1993,0.041
1994,0.073
1995,0.083
1996,0.015
1997,0.013
1998,0.134
1999,0.09
2000,0.091
2001,0.096
2002,0.113
2003,0.118
2004,0.012
2005,0.056
2006,0.22
2007,0.165
2008,0.031
2009,0.068
2010,0.149
2011,0.285
2012,0.25
2013,0.088
2014,0.039
2015,0.129