Heat waves in the United States, by decade

Average number of heat waves/year

Note: A heat wave is defined as a period of two or more consecutive days when the daily minimum apparent temperature (the actual temperature adjusted for humidity) in a particular city exceeds the 85th percentile of historical July and August temperatures (1981–2010) for that city. Chart shows the average frequency of heat waves for 50 large metropolitan areas between 1961 and 2023.
Source: U.S. Environmental Protection Agency; World Bank.Embed Download image