The National Weather Service issued heat alerts for about 156 million Americans, and 25 deaths have been reported in the United States, according to bluesky. Bluesky also reported that the government has no legal power to declare a heat emergency.

Forecasters expect several days of high temperatures across the central and eastern United States before the Fourth of July, and on Sunday temperatures of roughly 100 °F (38 °C) were recorded in parts of the country, including Phoenix, central Texas and much of the Southwest, according to the Guardian.

Extreme heat periods are becoming more frequent and intense as the climate warms, and communities across the United States are experiencing more dangerous heat index days, according to C2ES. The organization also noted that hot days are getting hotter and occurring more frequently worldwide, that 2024 was the hottest year on record with global average temperatures more than 1.5 °C above the 1850‑1900 average, and that the past ten years, from 2015 to 2024, were the hottest on record globally. In U.S. cities, the average rate of extreme heat events rose from two per year in the 1960s to ten per year between 2010 and 2020.