Weather
Arizona Rain: Flash Flood Risk Expands Wednesday
Flagstaff, Arizona – Monsoon moisture spreads west Wednesday, raising the risk of locally heavy rain and flash flooding across more of central and northern Arizona.
By Elliot Vaughn · 2026-09-22T10:40:58.980Z
Flagstaff, Arizona – Monsoon moisture spreads west Wednesday, raising the risk of locally heavy rain and flash flooding across more of central and northern Arizona.
According to the National Weather Service in Flagstaff, deep monsoon moisture is moving into eastern Arizona Tuesday before expanding west across most of central and northern Arizona Wednesday and Thursday. Increasing showers and thunderstorms could produce localized heavy rainfall and flash flooding.
A marginal risk of excessive rainfall covers portions of eastern Arizona Tuesday. The Wednesday outlook expands that marginal risk westward across a much broader area, including Flagstaff, Sedona, Winslow, Camp Verde, Payson and parts of the Interstate 17 and Interstate 40 corridors.
Rain chances also increase substantially Wednesday. The Weather Service graphic shows a 63% probability in Flagstaff, compared with 4% Tuesday. Sedona rises from 4% Tuesday to 34% Wednesday, while Payson reaches 46%.
Higher probabilities extend across eastern Arizona. Wednesday precipitation chances shown on the map include 62% at Heber Overgaard, 65% at Show Low, 67% at Window Rock and 72% at St. Johns.
The combination of thunderstorms and localized heavy rainfall means drivers should be alert for rapidly changing conditions, particularly around low water crossings and other flood prone locations. Never drive through a flooded roadway.
The wetter pattern expands Wednesday and remains a concern Thursday as monsoon moisture continues across central and northern Arizona. Residents and travelers should monitor National Weather Service updates as showers and thunderstorms increase.