An Extreme Heat Warning is in effect across the Phoenix metropolitan area, in Arizona, as the National Weather Service (NWS) warns of “dangerously hot” conditions that could push temperatures well above seasonal norms and pose a serious risk to public health.
The NWS in Phoenix said warnings for “major heat risk” will remain through Tuesday, until Tuesday night, with afternoon highs expected to climb between 105°F and 110°F.
Phoenix Braces for Peak Heat
The heat warning covers a wide stretch of central Arizona, including Phoenix, Mesa, Chandler, Scottsdale, Glendale, Tempe, and surrounding communities across Maricopa County.
According to the NWS, temperatures in the region are expected to peak on Tuesday, with highs nearing 107°F in Phoenix. Even by desert standards, this level of heat is notable for mid-May and raises the likelihood of heat-related illnesses, including heat exhaustion and heat stroke.
The warning is set to expire Tuesday evening, with gradual cooling expected beginning Wednesday, although temperatures will remain above average for much of the week.
Why This Heat Is Especially Dangerous
While Phoenix is known for its hot climate, this level of heat is unseasonable for May.
Historical averages show that typical highs in Phoenix for this time of year are closer to 95°F–98°F, meaning current temperatures are running around 10°C degrees above normal.
Early-season heat waves, like this, are often more dangerous because:
- People are less acclimated to extreme heat after winter and the cooler spring weather
- Nighttime lows—which are expected to remain in the 70s—limit the body’s ability to recover from the heat
- Prolonged exposure to these sorts of temrpeatures increases cumulative stress on the body
The NWS warns that extreme heat conditions can significantly raise the risk of heat exhaustion and heat stroke, particularly for outdoor workers, older adults, and those without a way to escape the heat.
How to Stay Safe in Extreme Heat
Officials are urging residents to take proactive steps to protect themselves.
What to do:
- Hydrate frequently: Drink water consistently, even if you don’t feel thirsty
- Stay indoors during peak heat hours: Between late morning and the early evening
- Use air conditioning or visit free cooling centers: Call 2-1-1 in Maricopa County for the locations
- Wear lightweight, loose-fitting clothing
What to avoid:
- Strenuous activity in the afternoon heat
- Leaving pets and children in vehicles, even briefly — the heat inside a car can kill in as little as 10 minutes
- Alcohol and caffeine, as they can contribute to dehydration
- Heavy meals that can increase body temperature
Anyone experiencing symptoms such as dizziness, confusion, nausea, or rapid pulse should seek immediate relief. Heat stroke is a medical emergency—call 911.
When Will It Cool Down?
Relief from the extreme temperatures is expected to begin midweek, with temperatures dipping closer to 100°F by Wednesday and falling into the upper 90s by Thursday.
While this marks a step down from peak conditions, forecasters caution that temperatures will remain warmer than average, and heat precautions should continue throughout the week.
Phoenix Forecast For The Week Ahead
Here’s how conditions are expected to evolve:
Tuesday: Increasing clouds, high near 107°F; light southwestern winds
Wednesday: Mostly cloudy early, then clearing; high near 101°F
Thursday: Sunny, high near 98°F
Friday: Sunny, high near 99°F
Saturday: Sunny, high near 100°F
Sunday: Sunny, high near 99°F
In summary, the worst of the heat will peak through Tuesday evening, followed by a gradual but incomplete cooldown—making heat safety essential for the days ahead.
What Scorching Temperatures Mean for Residents
While the most extreme temperatures are expected to ease after Tuesday, the current heat wave underscores how quickly conditions can become dangerous in the Southwest—especially early in the season.
With highs exceeding 105°F and well above normal for May, officials say residents should treat this as a serious and potentially life-threatening event, even in a region accustomed to extreme heat.