The Southwest Monsoons have finally started, bringing some much-needed rain to our region. But did you know that this year’s monsoon season is unusually late and dry compared to normal?

According to the National Weather Service, the average start date of the monsoon season in Pima County, AZ is June 15. Rainfall typically begins in the first week of July. However, this year, the first measurable rainfall at the Tucson Airport, the official climate site for Tucson, did not occur until July 22. That’s about three weeks later than usual!

Not only that, but the total rainfall so far this monsoon season has been well below average. As of August 31, the Tucson Airport has received only 2.32 inches of rain, which is 3.35 inches below normal. Rainfall amounts across the metro area have ranged widely from 0.75 inch to 3 inches, with some isolated higher amounts (1)(2).

The monsoon season is very important for our water supply, our vegetation, and our wildlife. It also helps cool down the temperatures and reduce the fire danger. But the monsoon season is also very variable and unpredictable. It depends on many factors, such as the moisture from the Gulf of California and Mexico, the wind patterns, and the local terrain.

One positive trigger for rainfall during the monsoon season in northern Arizona is the high elevation area known as the Mogollon Rim. This land feature acts as a trigger for showers and thunderstorms on most days during the monsoon season. In most years, the monsoon season begins to wind down across northern Arizona in September.

We hope that the rest of the monsoon season will bring us more rain and relief from the heat and drought. But we also need to be careful of the hazards that come with the monsoon season, such as flash floods, lightning, dust storms, and microbursts. Stay safe and enjoy the monsoon!🌧