High heat to dominate Phoenix from Sunday through Tuesday
PHOENIX, Arizona (Wednesday, June 25, 2025, 7:30 PM local time) — Dangerous heat is making a comeback in central Arizona, prompting First Alert Weather Days from Sunday through Tuesday next week.
Today’s high in the Phoenix Valley reached 103°F (39°C) — slightly below seasonal norms — but this short-lived relief won’t last. From Sunday, temperatures will surge well above average, with forecast highs climbing toward a blistering 110°F to 115°F (43°C to 46°C). The hottest day is expected to be Monday, which may challenge the record of 115°F (46°C) set back in 2013.
The National Weather Service has already issued an Extreme Heat Watch beginning Sunday morning through Tuesday evening, and this will likely be upgraded to a Heat Warning as forecast confidence increases. Normal highs for the final days of June in Phoenix hover around 107°F (42°C), making this incoming stretch well above normal.
Monsoon pattern still building across the Southwest
Meanwhile, monsoon moisture remains bottled up over New Mexico and northern Mexico, keeping eastern Arizona in a marginally unstable air mass. This is allowing only a slight chance for dry, high-based thunderstorms, primarily in the higher elevations. But change may be on the horizon.
With high pressure expected to shift early next week, a better inflow of tropical moisture could finally start feeding into Arizona. Thunderstorm chances should increase in the high country by Monday and Tuesday, and possibly make their way into the Phoenix metro by next Wednesday or Thursday.
There’s still a lot of atmospheric uncertainty, but trends suggest a potentially stormy setup leading into the Fourth of July weekend, particularly across northern and central Arizona.
