Phoenix weekly forecast includes extreme heat warning, possible monsoon activity

Think cool thoughts, Phoenix. With temperatures rising to potentially dangerous levels, weather officials have issued a midweek extreme heat warning.

And once that passes, the Valley could see a rumbling of monsoon storm activity.

The forecast calls for highs of at least 110 degrees throughout the week, with overnight lows between 85 and 90. But a large high-pressure system will cause a midweek spike.

The Extreme Heat Watch has been upgraded to a Warning for Tue – Thu. High temperatures will reach up to 112-116°F with morning lows in the 80s to 90°F in Phoenix. Areas of major HeatRisk is likely across the lower deserts and even some higher terrain. Stay cool! #azwx #cawx pic.twitter.com/NzErzFNvWC

— NWS Phoenix (@NWSPhoenix) July 5, 2026

In fact, temperatures are expected to reach about 114 degrees Tuesday, Wednesday and Thursday afternoon. To warn the public, the National Weather Service issued an extreme heat warning to run from 10 a.m. Tuesday to 8 p.m. Thursday.

The normal high for this time of year in Phoenix is 107 degrees. The city’s highest temperature so far this year is 112 degrees, a mark hit on June 16 and 26.

Phoenix trails close during extreme heat warnings

Extreme heat warnings trigger the daytime closures of hiking trails at Camelback Mountain, Piestewa Peak and South Mountain in Phoenix.

Health experts urge precautions during times of extreme heat like keeping hydrated, wearing light clothing and remaining indoors with air conditioning during the hottest times of the day.

The Salvation Army opens 10 heat relief stations across metro Phoenix during extreme heat warnings.

In addition, the Maricopa County Heat Relief Network provides free, cool spaces and other resources to people in need from May through September.

When will Phoenix start seeing monsoon storms?

Meteorologist Mark O’Malley of the National Weather Service in Phoenix said the Valley could see its first monsoon indicators after the extreme heat passes. But don’t expect widespread rainfall.

“We will look at some increasing moisture later this week and weekend,” O’Malley told KTAR News 92.3 FM on Monday morning. “Probably not everyone will see rain out of this, but there will be a few thunderstorms around in the high terrain. So, we’ll see increased moisture with increased wind gusts coming into the lower elevations of south-central Arizona late this week and into next week.”

March 29 was the last time measurable rain fell at Phoenix Sky Harbor International Airport, which the National Weather Service uses for the city’s official readings.

Arizona’s monsoon season runs from June 15 to Sept. 30, but it’s not uncommon for the early weeks to pass without storms.

KTAR News 92.3 FM’s Shira Tanzer contributed to this report.

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