Monsoon 2021 outlook: What to expect in Arizona in the months ahead

Gilbert Monsoon
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Posted at 7:00 AM, Jun 01, 2021
and last updated 2021-06-28 19:10:31-04

Monsoon 2021 is almost here!

It officially begins on June 15 and runs until September 30 each year.

This is the time of year when winds shift, bringing moisture from the Gulf of Mexico and the Gulf of California into Arizona.

As our sizzling summer heat builds in, that moisture rises and forms powerful thunderstorms.

These storms are typically a daily occurrence along the Mogollon Rim, where the mountains help provide the lift needed for the moisture-filled air to rise and form clouds.

Those storms can then move downslope into our lower deserts, like Phoenix.

From drenching rain and blinding dust to damaging winds and intense lightning, we see it all this time of year!

After back-to-back years of very little monsoon rainfall in Phoenix, hopes are high that this year will be a bit wetter and not as hot. Click here for a full breakdown of last year's monsoon.

But, what can we really expect out of Monsoon 2021?

Once again, temperatures are likely to be hotter than average. So, get ready for lots of 110-degree days.

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As far as rainfall goes, the outlook isn't as clear.

The Climate Prediction Center puts most of Arizona under equal chances for above-normal, below-normal, or near-normal rainfall. In other words, we'll just have to wait and see.

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The El Nino-Southern Oscillation (ENSO) is now in a "neutral" phase, meaning we are neither in an El Nino nor a La Nina and don't have those conditions driving the overall weather patterns across the U.S.

Additionally, there's a good chance of a below-normal Eastern Pacific hurricane season which means our potential to tap into moisture from remnant tropical systems near the Baja Peninsula is looking lower than normal.

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But, as we've seen in years past, all it really takes is one or two good tropical systems to make up for an entire monsoon's worth of rain. So, again, we'll just have to wait and see how things develop this year.

Average rainfall during the monsoon varies drastically across Arizona, but overall rainfall totals are trending down as our climate gets hotter and drier.

READ MORE: Impact Earth: What you need to know about Arizona's climate and trends that could impact you

Our new normal, which is the 30-year average from 1991-2020, is just 2.43 inches of rain in Phoenix during the monsoon. That's down from the previous 30-year average of 2.71 inches.

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Typically, the monsoon starts out dry in the desert with gusty winds, lightning, and dust storms before the real rain and flash flooding arrive in July and August.

The ABC15 Forecasters and our local National Weather Service teams are working to get you prepared for all of these threats.

Join us for Monsoon Awareness Week June 13-19. Each day we'll highlight a different threat and give you tips to keep your family and property safe. Follow us on Twitter, Facebook and Instagram for more information, too.