Phoenix’s monsoon outlook got worse. What does that mean?

If you were hoping for a wetter-than-normal monsoon season, you may have been praying to the wrong climate prediction model.

Last week, the Climate Prediction Center updated its precipitation forecast for July, August and September, and Arizona's chances of a wetter-than-normal monsoon went down. In May, the National Oceanic and Atmospheric Administration gave large chunks of Arizona a 40% chance of having above-average rainfall this summer and just a 27% chance of having below-average rain. Now, though, those chances are dead even with each other.


But that doesn't mean this monsoon will be dry, said National Weather Service meteorologist Alicia Ryan.

“All this means is we have equal chances," Ryan said. "We have equal chances of it being wetter but also equal chances of it being normal or below.”

The last two monsoons were abnormally dry — with just 0.74 and 0.15 inches of rain from June to September in 2024 and 2023, respectively — but those were outliers. The last close-to-normal monsoon was in 2022, when Phoenix got 2.23 inches of rain over those four months.

"Normal" for Phoenix is 2.43 inches, per the NWS. Even a below-normal monsoon this year could mean more rain than the last two summers combined.

At any rate, a wetter monsoon could still be in the cards, even if it's not as likely as it was a month ago. In 2021, Ryan noted, the early monsoon forecast called for below-average rain, only for Phoenix to get 4.2 inches of rain from June through September. That monsoon was the wettest in Phoenix since 2014, producing most of its rainfall in July and August.

Arizona remains in the middle of a decades-long drought, and five of the last six monsoons have provided the Valley with below-normal rainfall. A betting Arizonan (please don't bet on the weather) might take the under. After all, June has yet to see any measurable amount of rain at all.

But just because something got less likely doesn't make it unlikely. Rainy days may await us yet.