Tucson, Arizona – Triple-digit heat is tightening its grip across southern Arizona as Tucson heads toward a sweltering 99°F by Wednesday afternoon. With little wind and full sun expected, heat-related illness and vehicle overheating risks are rising—especially along busy roadways like I-10.
According to the National Weather Service in Tucson, Wednesday will bring partly cloudy skies and highs just shy of 100°F, with calm winds turning light by evening. Conditions intensify Thursday and Friday as temperatures climb to 100°F and 102°F, respectively, under mostly sunny skies. Nighttime lows will hover in the mid-to-upper 60s, offering little relief from the heat.
Hydration, sun protection, and avoiding strenuous outdoor activity from noon to 6 p.m. remain key for safety. Check car batteries and tires before driving—especially if traveling across exposed stretches of highway.
Looking ahead, a modest shift arrives this weekend. Saturday brings a 20% chance of showers with a high near 100°F, while Sunday’s rain chances rise to 30% under partly cloudy skies and a forecasted high of 99°F. Monday maintains a 20% chance of showers and a slightly cooler high of 98°F.
This early summer heatwave is typical for late May in Tucson, but the added chance of weekend rain is a pattern shift to watch. NWS will continue monitoring moisture trends into next week.
