Arizona's Monsoon Forecast: What to Expect This Tuesday, July 28.

Here is your Monsoon Outlook for Tuesday, July 28, 2026, provided by the US National Weather Service Flagstaff, Arizona . Graphic from U.S. National Weather Service Flagstaff, Arizona. Monsoon According to the US National Weather Service, Flagstaff, Arizona , some early morning shower and thunderstorm activity has developed. Expect these early storms to pause by 8-9 AM MST. Then, additional showers and thunderstorms will form by late morning or early afternoon, mainly over higher terrain. Some s