The last of Phoenix’s monsoon conditions — rain, thunderstorms, wind — are expected to occur this week.
Phoenix’s monsoon season this year has been warmer and drier than average, according to the National Weather Service. In fact, this year’s summer was the fourth-warmest on record and the monsoon is currently the third-driest, although Monday afternoon’s rain hasn’t been included in NWS data.
Despite last week’s national-headline-making haboob and thunderstorm, Phoenix’s monsoon season, which ends on Sept. 30, has been “somewhat drier than average across the metro,” said NWS Phoenix meteorologist Mark O’Malley. That dry trend is expected to continue throughout the rest of the month.
“Some localized areas have been fairly lucky with good rainfall,” O’Malley said, but “the majority of the metro has been below normal rainfall this monsoon.”
So far this monsoon, total rainfall counted at Phoenix Sky Harbor International Airport, where the NWS takes its measurements, has been only half an inch. More than half of that total — 0.29 inches — fell during the massive thunderstorm that hit the Valley on Aug. 25. From 1991-2020, according to NWS data, normal monsoon rainfall is 1.89 inches.
The last chance to add to 2025 rainfall will likely be Wednesday evening and Thursday of this week, O’Malley said. There is a “better than 50% chance” for the metro area to see rainfall during that period.
But how much? That will vary greatly depending on which part of the Valley you’re in. Some areas could see a 10th of an inch or less of rain, while others could see as much as an inch.
“The thunderstorms during monsoon can be very hit or miss,” O’Malley said. “Areas very close to each other can receive very disparate amounts of rain.”
Tonight was just a taste of what is to come this week as storm chances ramp up across our region, peaking late this week. Increasing moisture will lead to more widespread thunderstorm activity across the lower deserts, especially by Thursday and Friday. #azwx #cawx pic.twitter.com/3mbUyEsymL
— NWS Phoenix (@NWSPhoenix) September 2, 2025
So, however much rain your neighborhood gets this week, be sure to cherish it. Conditions will begin to dry out starting this weekend, and by early next week, the chances of rainfall and thunderstorms in the Phoenix area will go down to “essentially zero,” O’Malley said. Any thunderstorm activity will move east into New Mexico after that.
It’s possible Phoenix residents could get another glimpse of moisture pouring down from the sky, but by the time Phoenix reaches mid-September, generally “the monsoon season starts really dying down,” O’Malley said. Any rainfall that the area does see will likely be in the city’s mountainous regions.
So the next time the skies get dark, pull out that umbrella or raincoat. It may be the last time you get to use it this year.
