Yes, this summer really was as hot as you think it was

This summer was officially the hottest on record for the contiguous U.S., beating out 1936 and 2021 by 0.4 degrees Fahrenheit, according to NOAA. Temperatures ran 3 degrees above the 20th-century average, with August alone up 3.5 degrees. A separate analysis from Climate Central found that 293 million Americans, or 86 percent of the population, went through at least 30 days of unusually risky heat this summer. New Mexico, Nevada, Colorado, and Utah saw the most such days, with Colorado's summer temperatures running 4.4 degrees above normal.

The heat is doing more than making days uncomfortable. Nights are warming faster than days, so homes and bodies get less of a chance to cool down before the next hot day hits. That matters for anyone without reliable air conditioning or a home that holds heat poorly, since extreme heat can worsen heart and lung conditions, and older residents in particular have a harder time cooling off on their own.

Scientists also flagged a developing El Niño, a warm-water pattern in the Pacific that adds heat to the atmosphere, as a factor in this summer's records. Because that El Niño is still building rather than peaking, researchers expect it could push next summer's temperatures even higher. For homeowners, that points to more summers like this one ahead, making a house's ability to stay cool, and to shed heat overnight, an increasingly practical concern rather than just a comfort issue.