July Sets Record as Hottest Month in U.S. History Amid Multiple Heat Domes

July 2024 became the warmest month ever documented for the contiguous United States, with the average temperature 1.8 °C (3.3 °F) above the 20th-century average, NOAA reported. The new record surpasses the previous high set in July 1936 and July 2012, extending back to the start of reliable measurements in 1895.

Three separate heat-dome events dominated the month, trapping high temperatures over the western states, the Rockies, the upper Midwest, the Gulf Coast and the Southeast. Wyoming experienced its warmest July on record, with temperatures more than 5 °F above normal.

The extreme heat coincided with widespread wildfire smoke from large blazes in the Pacific Northwest of the United States and Canada. Scientists said the combination of elevated temperatures and extensive fires is being amplified by human-driven climate change, which is driven by emissions from coal, oil and gas.

A recent AP-NORC poll indicated that nearly half of U.S. respondents said the heat had a major impact on their electricity bills, while about 40 % said it altered travel plans. Two-thirds reported disruptions to outdoor activities and roughly half said exercise routines were affected, marking a broader impact than in similar surveys two years earlier.

"The bottom line, though, is that we expect to set record global temperatures as long as carbon emissions continue to warm the planet, and typically these records are set during major El Niño events," said climate scientist Michael Mann of the University of Pennsylvania.

An unusually strong El Niño developing in the Pacific Ocean is expected to raise the likelihood that next year could break global temperature records, potentially making 2024 the warmest year on record.

The report also noted ongoing political debate over energy policy, referencing statements by President Donald Trump that have dismissed climate science and advocated for increased fossil-fuel production.