Arizona's 2026 Monsoon Ends With a Stormy Finish

Arizona's monsoon season, which the National Weather Service defines as June 15 to September 30, comes to an end today. For most of the summer it was an unremarkable season in the state's golf hubs. Then, in its last few days, a late-September storm brought some of the heaviest rain of the year and a wave of flood warnings.

How Wet Was It?

We compared rainfall at the official weather stations for four of our golf regions with the 1991–2020 normals for the same dates, from June 15 through September 29. Figures for the last few days are preliminary.

• Phoenix (Sky Harbor): 2.46 inches, against a normal of 2.41, with measurable rain on 13 days.
• Tucson (airport): 5.73 inches, against a normal of 5.67, on 26 days.
• Flagstaff (airport): 8.34 inches, against a normal of 7.64, on 33 days.
• Las Vegas (Harry Reid): 0.50 inches, against a normal of 1.04, on 6 days.

In short:

• Phoenix and Tucson finished almost exactly at normal. Tucson's wettest day was August 31, with 0.84 inches.
• Flagstaff was the wettest of the four, about 9% above normal, helped by a very wet spell in mid-July.
• Las Vegas had only about half its normal monsoon rain, with measurable rain on just six days.

A Stormy Finish

The biggest single event came at the very end. On September 28 and 29, a low-pressure system to the north and northwest interacted with the remnants of Hurricane Polo, according to FOX 10 Phoenix, bringing thunderstorms, flood watches and flash flood warnings across much of the state.

• Phoenix recorded 0.17 inches on September 28 and 0.45 inches on September 29, its wettest day of the season.
• Flagstaff recorded 0.62 inches and then 1.65 inches: 2.27 inches in two days, more than a quarter of its entire monsoon total.
• Tucson recorded 0.35 inches on September 29, and Las Vegas 0.30 inches over the two days, more than half of its season.

The storm days were also a hard test for our own forecasts. In the Phoenix area in particular, conditions for golf turned out better than our playability scores predicted. We have since changed how we score scattered thunderstorms, and we publish how our forecasts compare with what actually happened on our track record page.

What It Means for Golfers

With the monsoon over, the desert usually settles into its driest and most pleasant stretch of the year. In Phoenix, the October normal is little more than half an inch of rain, and daytime highs fall back into the 80s. Two things are worth keeping in mind:

• Soft ground after the storm: courses that took heavy rain on September 28 and 29 may be wet for a few days, with cart-path-only rules or temporary closures. Our playability scores take recent rain into account for each course.
• Overseeding continues: many courses are closed or restricted while their winter ryegrass grows in, and the rain can shift reopening dates. See our article on Arizona's 2026 overseeding season.

Check the forecast for any course on our Arizona and Nevada golf weather pages. For how to stay safe when storms do build, see Lightning and Golf: How to Stay Safe on the Course.

Sources: daily observations and 1991–2020 normals from NOAA's Applied Climate Information System (Phoenix Sky Harbor, Tucson International, Flagstaff Pulliam and Harry Reid International airports), retrieved September 30, 2026; storm cause from FOX 10 Phoenix, September 29, 2026; monsoon season dates from the National Weather Service.

Photo: monsoon rains near Camp Verde, Arizona, by Brady Smith, U.S. Forest Service, Coconino National Forest, licensed under CC BY-SA 2.0, via Wikimedia Commons. Resized from the original.