PHOENIX — Phoenix wrapped up its annual six-month warm season this week after the Southwest experienced an unprecedented fall heat wave where daily maximum temperatures in the hottest city in the United States topped 110 degrees Fahrenheit (43.3 degrees Celsius) in October for the first time ever recorded – four times during the month so far.
The National Weather Service said the heat wave that extended into October caused Phoenix to set an annual record of 70 days with highs reaching or passing 110 F. September 19, 2010 was previously the last date in the year that Phoenix had recorded such high temperatures.
“We’re done with the extreme weather now, but we may not be done with the records for the year,” said Sean Benedict, chief meteorologist for the weather service in Phoenix. “We are cooling down now, but we do have a forecast of 100 degrees next Thursday.”
“Whew, that should hopefully end the latest round of high maximum temperature records,” says the Arizona State Climate Office said on the social platform X. “Phoenix had 19 new records and 2 ties. Tucson had 18 new records and no ties. Flagstaff had 10 new records and 1 tie. Many of the new records were set at different levels.”
The high temperature in Phoenix on Friday was expected to reach 79°F (26.1°C) with cooler temperatures continuing through the weekend and into next week.
Public health officials in Maricopa County say 389 heat-related deaths have been confirmed so far this year, with a further 292 deaths under investigation for possible heat causes. Officials recorded 645 heat-related deaths last year in the county of about 4.5 million residents, including Phoenix.
The Medical Examiner’s Office in Arizona’s Pima County, home to Tucson, the state’s second most populous, reported that there 131 heat-related deaths so far this year.
The coroner/medical examiner’s office in Nevada’s Clark County said it determined heat was a factor in at least 402 deaths in mid-October.
The published number of heat-related deaths this year in New Mexico is three months behind, so the hottest months of the year are not taken into account. But the cases of heat-related illnesses reported by emergency rooms across the state this year stood at 957 from Friday.
The University of New Mexico’s Office of the Medical Investigator has experienced a tenfold increase in cases over the past two years in suspected deaths among migrants near the U.S.-Mexico border, most of which are due to heat-related causes.