Highlights
- First Alert Weather Days are in effect through Sunday, with Monday's high forecast near 113 degrees.
- Overnight lows will hover around 90 degrees through the weekend, limiting recovery time.
- Rising humidity will push dew points into the upper-50s and low-60s starting Wednesday through Friday.
- A slight chance of Valley showers is being tracked for Thursday night into Friday morning.
Phoenix is entering one of its more punishing stretches of the summer, with First Alert Weather Days in effect through Sunday as highs hit 110 degrees or hotter across the Valley, according to Arizona's Family meteorologist Pete Mangione. Monday is forecast to peak near 113.
The heat is compounded by limited overnight relief. Lows will hover around 90 degrees through the weekend, reducing the window for the Valley to cool before the next day's peak. The National Weather Service confirmed daily highs across the lower deserts between 109 and 113 degrees throughout the week, with overnight lows warming well into the 80s.
Humidity will become an added factor mid-week. Dew points currently sit in the mid-50s but are expected to climb into the upper-50s and low-60s starting Wednesday and continuing through Friday, according to Mangione's forecast.
Isolated storms are clipping eastern Arizona Monday and Tuesday, with storm coverage expected to increase in the High Country later this week. Gusty outflow winds from that activity could reach the Valley. Mangione is also tracking a slight, though still uncertain, chance of Valley showers Thursday night into Friday morning.
KTAR and Fox 10 Phoenix are also reporting on the extreme heat warning, with Fox 10 noting temperatures reaching 112 degrees as the warning period began. Three hikers required rescue from Phoenix trails in a single day as the heat returned, Fox 10 reported.
The First Alert Weather Days designation runs through Sunday.
Sources
Every factual claim in this article traces to one of the sources below. See how we work for the editorial process.
- AZ Family (3TV/CBS5) retrieved 17/08/2026 19:55
- weather.gov retrieved 17/08/2026 19:55
- Fox 10 Phoenix retrieved 17/08/2026 19:55
Authored by The Scottsdale Signal. Drafted by AI from primary-source material under our beat-specific editorial guides; reviewed by humans before publish under our five-gate process. Sources retrieved at 17/08/2026 19:55. Every claim traces to a source.
