ملف:U.S. Temperature Climate Normals.png

English: "Annual U.S. temperature compared to the 20th-century average for each U.S. Climate Normals period from 1901-1930 (upper left) to 1991-2020 (lower right). The U.S. Climate Normals collection has 10 versions: 1901-1930, 1911-1940 and so on through 1991-2020. In the image below, we’ve compared the U.S. annual average temperature during each Normals period to the 20th-century average (1901-2000). The influence of long-term global warming is obvious: The earliest map in the series has the most widespread and darkest blues, and the most recent map has the most widespread and darkest reds."