Image caption
(top) Average temperature for the contiguous United States in May 2021 compared to the twentieth-century average. Places that were cooler than average are red; places that were cooler than average are blue. (bottom) May temperature compared to the twentieth-century average each year from 1895–2021. U.S. May temperature has risen by 0.09 degrees Fahrenheit per decade. NOAA Climate.gov image, based on data from NCEI.