US summer was hottest on record, NOAA says

The contiguous United States had its hottest summer on record, the National Oceanic and Atmospheric Administration said Wednesday, with the June-to-August average temperature reaching 74.4F, or 23.6C.

NOAA said the average for the Lower 48 states was 0.4F above the previous records set in 1936 and 2021. Four of the hottest US summers on record have occurred within the past five years, with 2022 and 2024 ranking fourth and fifth.

August was also the warmest August since records began in 1895, with an average temperature of 75.6F. NOAA had previously said July 2026 was the hottest of all months ever recorded in the United States.

Climate scientists linked the trend to human-caused climate change, driven mainly by the burning of fossil fuels. Andrew Dessler, a climate scientist at Texas A&M University, told AFP the warming was occurring as scientists had forecast decades ago.

Karin Gleason, chief of the monitoring section of NOAA's National Centers for Environmental Information, said the 2026 summer had surpassed the Dust Bowl summer of 1936 by a narrow margin. She said the 1936 record was driven by extreme daytime highs, while the 2026 record was driven by unusually warm overnight lows.

Zeke Hausfather of Berkeley Earth said the record summer was in line with expectations from human-caused climate change and warned that hotter summers increase heat stress, cooling demand and pressure on infrastructure and public health systems.

Precipitation was below average, ranking in the driest third on record for both August and the June-to-August period. Drought covered nearly 60 percent of the contiguous United States by September 1. NOAA also cited Lake Mead, the largest US reservoir, dropping to its lowest level on record, while severe storms brought heavy rain in central Indiana.

Alaska's August and summer average temperatures ranked in the warmest third of records. Hawaii had its third-warmest August and a summer in the warmest third, while Hurricane Lala brought heavy rain that contributed to Hawaii's second-wettest August on record.

The data came as a strengthening El Nino pattern was expected to peak between October and December and fuel record heat in 2027. The pattern could also push 2026 past 2024 as the hottest year on record.

University of Pennsylvania climatologist Michael Mann told AFP that warming could be prevented from getting worse. He said the consensus among climate scientists is that surface warming will stop when zero carbon emissions are reached, and that clean energy technology exists to do so.