PHOENIX – In the wake of the hottest August day ever recorded in Phoenix, an ongoing extreme heat warning has been extended through the weekend.

The National Weather Service (NWS) activated the warning, which covers the Valley and most of southwestern Arizona, late last week.

It was scheduled to expire Friday at 8 p.m., but now it will run at least through Tuesday evening.

Why was metro Phoenix extreme heat warning extended?

“The main reason we extended the extreme heat warning is because we’re going to continue to see areas of major heat risk into early next week,” Gabriel Lojero of the NWS in Phoenix told KTAR News 92.3 FM on Friday afternoon.

The Phoenix weather forecast calls for high temperatures of 110-113 degrees in the coming days, along with a slight increase in humidity that will make conditions worse. The normal high for this time of year is 105 degrees.

“Our overnight low temperatures are still going to remain pretty elevated in the upper 80s to around 90 degrees,” Lojero said. “So as a result, there’s not going to be as much of overnight relief for the body to recuperate.”

While the conditions are hot enough to extend the extreme heat warning, it’s actually a break after two days of record-setting heat.

On Thursday, it reached 118 degrees at Phoenix Sky Harbor International Airport, which the NWS uses for the city’s official readings. It was the hottest August day ever recorded in Phoenix and broke a 120-year-old heat record for Aug. 7. It also tied July 9 for the hottest day of 2025.

A day earlier, Phoenix reached 116 degrees to break a 30-year-old record for the date.

“The good news is that we’re not expecting temperatures of those extremes because we’re not seeing the record high pressure strength that we saw the last couple of days,” Lojero said.

How to stay safe during extreme heat warnings

Due to the dangerous conditions, the following Phoenix hiking trails are restricted from 8 a.m. to 5 p.m. on extreme heat warning days:

  • Camelback Mountain: Echo Canyon Trail and Cholla trail.
  • Phoenix Mountains Preserve: Piestewa Peak Summit Trail and associated trails.
  • South Mountain Park and Preserve: Holbert Trail, Mormon Trail, Hau’Pal Loop Trail and access to the National Trail from the Pima Canyon Trailhead.

“Given that we extended the extreme heat warning through the weekend into early next week, it’s a good reminder that people need to take all the necessary heat precautions: Try to limit your time spent outdoors, drink lots of water, keep yourself hydrated,” Lojero said.

Another tip is to wear light, loose-fitting clothing.

“If you have to be outside for an extended period of time, try to take frequent breaks in the shade,” Lojero said.

KTAR News 92.3 FM’s Bill O’Neill contributed to this report.

We want to hear from you.

Have a story idea or tip? Pass it along to the KTAR News team here.