Wednesday could bring evening storms. Storms could bring shifting winds across the Valley.
Storm Chances Arrive Late Wednesday
The National Weather Service in Phoenix says the best chance for storms will be near foothills and higher terrain, with activity potentially pushing into lower desert communities later in the evening. Wednesday night brings a 30% chance of showers and thunderstorms, a low near 80, and east winds gusting as high as 20 mph.
Storm outflows could produce stronger gusts than the background winds, briefly reaching around 30 to 35 mph in parts of the Valley. Storm outflows may bring gusty winds and localized heavy rain.
Thursday Stays Hot Before A Briefly Dry Friday
Thursday will remain sunny and hot, with another high near 99 degrees and a slight chance of showers or thunderstorms after 5 p.m. The overnight storm chance fades before Friday, which is expected to be sunny with a high near 99 and lighter winds.
Saturday Brings The Week’s Peak Heat
Saturday looks drier, with temperatures around 100 degrees.
Late-September Heat and Monsoon Context
The National Weather Service Phoenix climate report says Tuesday, Sept. 22, reached 100 degrees, 1 degree above the 99-degree normal. For Sept. 23, it lists a normal high of 98 degrees and a record high of 108, recorded in 2001, 2002 and 2011. Late-September showers fall after the period when monsoon winds generally shift, though timing varies. NOAA Climate.gov says wind patterns generally return to westerly by early to mid-September, while noting variability in the monsoon’s onset and end. Arizona and New Mexico receive more than 50% of their average annual precipitation from the North American Monsoon during July through September.
Tuesday reached 100 degrees. For now, the practical forecast is simple: expect serious heat through Saturday and keep an eye on the sky Wednesday and Thursday evenings.
