The National Weather Service has put metro Phoenix under an extreme heat warning from 10 a.m. Tuesday through 8 p.m. Thursday, signaling several days of dangerously high temperatures and health risks for valley residents.
Expected conditions and timing
Forecasts show daytime highs around 108 degrees, with some model guidance indicating peaks near 110°F. Overnight temperatures are expected to remain unusually warm, with lows holding well into the 80s. The warning encompasses the lower deserts and is set to span the middle of the week.
"Extreme Heat Warnings go into effect today and on Wednesday for the lower deserts and last through at least Thursday."
Thursday will mark the Valley’s 47th day under an extreme heat warning in 2026, one day shy of the record of 48 set in 2020.
Local impacts and public services
Extreme heat warnings trigger several public-safety actions and advisories across Phoenix and the broader Valley. Land managers typically close popular daytime hiking routes — including Camelback Mountain, Piestewa Peak and South Mountain — to prevent heat-related emergencies. The warning also prompts agencies and nonprofits to increase outreach and activate cooling resources.
- Maricopa County reports 136 heat-related deaths so far this year, about double the number at this point in 2025.
- The Maricopa County Heat Relief Network runs free cooling locations and other services from May through September.
- The Salvation Army establishes 10 heat relief stations across the Valley during extreme heat warnings.
Health guidance for residents
Health officials say the combination of high daytime temperatures and warm nights increases the risk of heat illness, especially for older adults, young children, people with chronic medical conditions, and those without reliable access to air conditioning. Recommended precautions include staying hydrated, limiting outdoor activity during peak heat, wearing light clothing, and spending time in air-conditioned spaces when possible.
| Item | Detail |
|---|---|
| Warning period | 10 a.m. Tuesday — 8 p.m. Thursday |
| Forecast high | About 108°F (near 110°F at times) |
| Nights | Lows in the 80s |
| Heat-related deaths (Maricopa County) | 136 so far this year |
Officials advise avoiding strenuous outdoor exercise during the hottest hours and monitoring vulnerable neighbors and family members. Workers who must be outside should have access to shade, frequent breaks and water.
Short-term forecast and what to watch
While extreme heat will dominate the early part of the week, meteorologists say the monsoon pattern could return later this week and into the weekend. There is at least a slight chance for thunderstorms from Thursday night through Monday, with Friday currently showing the highest chance for storms at about 40%. Any thunderstorm activity could bring localized cooling but also hazards such as flash flooding and gusty winds.
Residents should plan for sustained high temperatures through Thursday and monitor updates from the National Weather Service and local health agencies. Cooling centers, the Heat Relief Network and Salvation Army stations are available to people who need relief; check agency websites and local announcements for locations and hours.
With the Valley approaching a record number of extreme-heat days for the year, public health officials reiterated that simple precautions — staying hydrated, spending time in cooled environments, and checking on at-risk people — can reduce the risk of heat-related illness.
Gabriela Montoya
State Correspondent, WE NEWS
