What's the outlook for monsoon 2021?

Precipitation outlook for June, July and August, according to the Climate Prediction Center.
Posted at 3:52 PM, Jun 09, 2021

TUCSON, Ariz. (KGUN) — Monsoon 2020 was pretty much a "non-soon" and left many southern Arizona residents high and dry. The summer of 2020 was the hottest to ever be recorded dating back to the late 1800s and the lack of rain was a reflection of the extreme heat.

Most communities didn't even come close to measuring their average monsoon rain totals. In Tucson, at the airport, only 1.62 inches of rain fell. 2020 ranked as the second driest monsoon ever recorded -- just slightly behind 1924 when only 1.59 inches of rain fell.

Now we look forward to monsoon 2021 with a renewed hope that seasonal thunderstorms will return and bring much-needed, much-overdue rain back to the desert.

Monsoon has many influences and one of those is tropical activity. Let's head to the Eastern Pacific because storms that develop in this area can help feed moisture into our North American monsoon.


El Niño and La Niña play a major factor in tropical storm development. Right now, sea surface temperatures are running pretty close to average so we're in a neutral position. The neutral position is expected to continue through the summer, but a shift to a weak La Niña is forecast into late summer and early fall.

This may limit tropical storm activity in the pacific but could increase the number of storms in the Atlantic. Sometimes, those storms cross the Gulf of Mexico and feed into monsoon moisture over northern Mexico.

The outlook for eastern pacific tropical activity shows close to average storm formation with 16 named storms... eight of which will become hurricanes and three of those expected to become major hurricanes.

We also look at forecast models to get an idea of the long-range outlooks. Currently, the Climate Prediction Center is forecasting temperatures to run much above average and rainfall to run right at or slightly below average during monsoon.

So, this brings us to our prediction for this year's monsoon. For 2021, we expect an average monsoon that will include some, hot dry stretches and with a few active thunderstorm days in between.