Extreme Heat Grips Phoenix With Record-Challenging Temperatures Ahead

PHOENIX, AZ — The Phoenix metro isn't getting much of a break from the heat, and forecasters say an even hotter stretch is on the way later this week.

An Extreme Heat Warning remains in effect through Wednesday evening for Phoenix, the Imperial Valley and the Lower Colorado River Valley, where dangerously high daytime temperatures and warm overnight lows continue to pose health risks.

According to the National Weather Service, highs will climb between 108 and 115 degrees Monday, while overnight temperatures will only fall into the upper 80s and low 90s.

That lack of overnight cooling is the main reason the warning will stay in place for parts of the region even after it expires elsewhere Monday evening.

Temperatures may ease slightly Tuesday, with highs dropping by 1 to 2 degrees, but they'll still run 4 to 6 degrees above average.

There's a slight chance of thunderstorms this week, though most of the activity is expected to stay north and east of the Valley. Forecasters say northeastern Arizona has the best chance of seeing storms, while south-central Arizona and the lower deserts have only a slim chance, with Tuesday morning offering the best opportunity for any isolated development around Phoenix.

The bigger concern is the forecast heading into the weekend.

A strengthening high-pressure system is expected to send temperatures soaring Friday and Saturday, potentially producing some of the hottest weather Phoenix has seen this year.

The National Weather Service estimates a 65% chance that Phoenix Sky Harbor will tie or break its record high of 116 degrees on Friday and a 50% chance on Saturday. Forecasters are already signaling that another widespread Extreme Heat Warning will likely be needed by the end of the week.

Looking ahead, a more typical monsoon pattern is expected to return next week.

While that could bring increased thunderstorm activity across Arizona, the best chances are expected over the higher terrain of northern and southeastern Arizona, with only limited storm potential in the Phoenix metro.