August Heat Shattered Records in These 6 Counties

woman leaning on white concrete surface beside swimming pool during daytime

https://climatecrisis247.com/wp-content/uploads/2025/09/x912jiy57ju-150x150.jpg

Around the world, temperatures soared well above historical norms in August 2025. In four countries – Brunei, Japan, Martinique, and the United Arab Emirates – average August temperatures either matched or exceeded all-time highs, according to Yale Climate Connections. Additionally, data from the National Oceanic and Atmospheric Administration shows that this past August now stands as the third hottest on record globally. According to NOAA, last month’s heat has raised the odds that 2025 will rank among the five hottest years in history to over 99%.

In the United States, temperatures last month – while well above average – were not as extreme as they were in many other parts of the world. Across the Lower 48, the average temperature in August 2025 was 73.4°F, about 1.3°F warmer than the 20th century average for the month, and about 1.6°F cooler than in 1983, the hottest August on record, according to NOAA.

But while average temperatures did not break any records last month on the national scale, at the local level, there were half a dozen counties for which average temperatures in August 2025 either broke or matched all-time highs.

Using data from NOAA, Climate Crisis 247 identified the U.S. counties where average August temperatures hit historic highs in 2025. We reviewed average temperatures in August 2025 for over 3,100 counties and county equivalents, and identified those for which last month’s average temperature was the highest since record keeping began in 1895. Only counties where August temperatures hit a record high in 2025 rank on this list. All supplemental temperature data is from NOAA. Population data are five-year estimates from the U.S. Census Bureau’s 2023 American Community Survey. Counties are listed in ascending order, based on the difference between their average temperature in August 2025 and the average August temperature from 1901 to 2000.

The counties on this list span two states on opposite ends of the country – Florida and Oregon – and are collectively home to more than 5.5 million Americans.