Phoenix is gearing up for a classic late May scorcher on Sunday, May 24, with clear skies, quick warming and a high close to 99°F on tap. Overnight, temperatures are expected to slip only to around 72°F, and winds should stay mostly light through the afternoon.
According to the National Weather Service in Phoenix, things get a bit more interesting late Sunday night into Monday, May 25. Isolated showers and a few thunderstorms are possible, mainly over higher terrain south and east of the Valley, and any storms that form could kick out brief, gusty outflow winds up to about 25 mph. Forecasters are also eyeing a midweek shift toward slightly cooler but windier conditions, with stronger gusts possible on Wednesday, May 27 as higher momentum winds mix down to the surface.
Afternoon Heat And Timing
Temperatures will climb quickly after sunrise, pushing into the mid 90s by early afternoon and topping out near 99°F later in the day. Afternoon humidity is expected to stay low, often in the mid teens, so it will be a dry kind of hot, but still risky for anyone out too long in the sun. If you are planning outdoor activities, try to stack them in the morning or evening and bring plenty of water and a way to find shade.
Sunday Night Gusts And Small Rain Chance
Late day thunderstorms that pop up over eastern and southern high terrain could send outflow winds into parts of the East Valley and northern Pinal County Sunday evening. That could mean gusty, erratic winds and a brief chance of dust in more exposed spots. Most of the Phoenix metro should stay dry, but drivers should be ready for sudden wind shifts and bits of loose debris if storms fire to the south. A few brief pockets of light rain are possible overnight, though meaningful rainfall totals are not expected.
Midweek Wind Shift And Fire Weather
By Wednesday, May 27, stronger midlevel winds are expected to mix down to the surface, bringing gusts commonly in the 20 to 30 mph range along with a short lived drop of about 5 to 10°F from recent highs. Paired with afternoon relative humidity around 10 to 20 percent, those winds will bump up fire weather concerns across dry fuels, especially in foothill and desert scrub areas. Avoid outdoor burning and secure loose items before the windier afternoons arrive.
Heat Relief And Safety Resources
Maricopa County and the City of Phoenix have opened the regional Heat Relief Network for the warm season, and the city is running a 24/7 respite site downtown for anyone who needs a cool place to rest. For maps of cooling centers and hydration stations around the Valley, check the Maricopa County Heat Relief Network. Never leave children or pets in parked cars, and check in on elderly neighbors during the hottest part of the day.
Plan outdoor time for the cooler hours, keep water close at hand and be ready for gusty, changeable conditions Sunday night and again around midweek. Updates will follow if any watches or advisories are issued.
