The desert oven is officially preheating. Under clear skies Thursday morning, May 21, Phoenix started out with comfortable readings but is already warming fast toward an afternoon high near 95°F. Overnight lows will dip only into the upper 60s, with light south-southeast breezes offering limited relief.
Weekend And Memorial Day Outlook
Heat builds into the holiday stretch. Forecast highs climb into the mid-90s Friday and Saturday, then push into the upper 90s and around 100°F on Sunday, May 24. Memorial Day itself, Monday, May 25, is expected to hover close to 99°F across the metro under mostly sunny, dry skies.
Afternoon humidity will stay low, so that classic dry heat will feel especially fierce on asphalt, concrete and hiking trails. Outdoor plans are still very much in play, but expect the sun to do most of the talking in the middle of the day.
Fire Weather And Mountain Lightning Risk
Early next week brings a slight chance of afternoon or evening thunderstorms over the higher terrain. Forecasters say most of these storms are likely to produce little actual rain and instead feature dry lightning and gusty outflows, conditions that can easily spark new wildfires, especially on Monday afternoon.
The fire weather concerns and the broader warm, dry pattern are detailed by the National Weather Service Phoenix.
How To Stay Safe
If you need to cool off, Maricopa County's Heat Relief Network maps cooling centers, respite sites and hydration stations across the Valley. Call 2-1-1 for help finding a nearby location.
Stay smart in the heat: avoid strenuous outdoor work during the hottest hours, drink plenty of water throughout the day, check in on older neighbors and never leave people or pets in parked cars, even for a short time.
