A summer marked by extreme, record-setting heat in the U.S. comes to a close

Phoenix also set a record this year for the total number of days at or above 110 degrees, with 61 so far. The previous record of 55 days was set in 2023.

Last year, Phoenix sweltered through a record 31 straight days at or above 110 degrees, obliterating the previous record of 18 consecutive days set in 1974.

Over the last week, cooler weather has finally brought some relief to Arizona’s capital city. Phoenix last recorded a temperature at or above 110 degrees on Sept. 10. But the cooldown may be short-lived, as weather forecasts show that the city may see temperatures in the triple digits again next week.

Overall, the months of extreme temperatures are part of a worrying trend for the desert metropolis, which already has a reputation for unrelenting heat. Climate change is increasing the frequency, duration and intensity of heat waves, and Phoenix’s hottest five summers in recorded history have all been in the past 11 years, according to the National Weather Service.

The conditions have been deadly. Maricopa County, where Phoenix is located, has confirmed 256 heat-related deaths so far this year, with 393 more under investigation, according to county records. Last year, at least 645 people died from heat-related causes in Maricopa County, a 52% increase over the previous year.