The monsoon; or Arizona Monsoon, is a reversal of the mid and upper-level winds. Usually winds go from west to east, but a few months during the summer, the jet stream shoves far north, allowing for a calmness to form a ridge of high pressure over the Southwestern United States. States affected within this is usually New Mexico, Arizona, California, Nevada, Utah, and Colorado as moisture comes in our of Northern Mexico, often aided by strong tropical activity to the south.
There are dry years, and there are wet years. For some, the 2025 season packed a punch. It wasn’t too much of a punch for a lot of Northern Arizona, as was the 2024 season, but this should be a change for the season to come.
Typical season ranges from June 15th to September 30th.
Last year, every other source stated a dry season. I used a five part algorithm and produced a season to be average to above average across the state. The season turned out to be average to above average as a result.
Using the same algorithm as the 2025 season, the preliminary numbers show that two have above average, two at average, and one at below average for rainfall for the 2026 Monsoon Season. With that in mind, the preliminary will go with the majority, which would be between the average and above average algorithms. As such, it looks like it will be another back to back season for an elevated monsoon.
Final forecast will be issued in the coming months, but for now the preliminary will stand as we build into the strong El Nino coming up.
Raiden Storm
Master General Meteorol0gist