Flagstaff, Ariz. – September storms will slam northern Arizona late Thursday, with heavy showers and thunderstorms likely to slow travel and threaten outdoor events. Drivers along I-40 should prepare for wet roads, limited visibility, and sudden wind gusts as storms roll through after 8 a.m.
According to the National Weather Service, rain chances climb sharply Thursday morning, with thunderstorms possible throughout the day and evening. The strongest cells could bring lightning, brief downpours, and gusty winds topping 25 mph. Showers linger overnight, keeping conditions damp into early Friday.
Travelers should allow extra time, especially on I-40 and U.S. 89, where slick pavement and ponding are possible. Those with outdoor plans, including early fall festivals and school sports, should keep backup indoor options. NWS advises avoiding exposed areas during lightning and checking local advisories before heading out.
Friday will bring cooler air but another round of scattered storms, especially during the afternoon and evening. Sunshine returns Saturday afternoon, offering a calmer window before drier air builds for the start of next week.
Temperatures remain seasonable, ranging from the low 70s during the day to the upper 40s at night. Southwest winds will increase early next week, with gusts near 30 mph Tuesday and Wednesday.
Rain chances drop off after Saturday, but storms remain possible in higher terrain through the weekend. More advisories could be issued if conditions intensify.
Five Day Forecast for Flagstaff, AZ
- Friday: High near 72, showers and thunderstorms likely. Low near 48.
- Saturday: High near 73, morning showers, then clearing skies. Low near 48.
- Sunday: Mostly sunny, high near 76. Low near 47.
- Monday: Sunny, breezy, high near 78. Low near 46.
- Tuesday: High near 77, windy with gusts up to 30 mph. Low near 46.
