Weather in the Sonoran Desert

Phoenix—as part of a large swath of the US southwest and northern Mexico-—is located in the Sonoran Desert.

While most of the country has four seasons, the Sonoran Desert actually has five: autumn, winter, spring, dry summer, wet summer.

Wet summer here is known as monsoon season, which is technically defined as three consecutive days of the dew point being over 55 degrees.* What does that mean? It’s humid. It’s not like humidity in other parts of the country, but it matters.

*The National Weather Service redefined monsoon season as June 15 to September 30. I’m guessing so those silly enough to vacation in southern Arizona in the summer would have a fighting chance of learning that there is the potential for fierce thunderstorms, flash flooding, and dust storms. But the dates aren’t as relevant as actual weather factors. We haven’t had a monsoon storm yet this year.

“It’s a dry heat.” And it is! Sometimes. (During dry summer. And October.) And it matters!

This sentiment doesn’t mean that it’s hot but never feels hot.

The humidity during dry summer is generally less than 10%. At that humidity level, for many people, 90 degrees is pretty comfortable, especially if you’re not in direct sun. I can run in the low 90s without complaint.

(Being in the shade makes a much bigger difference here than it did back east. When it’s humid, the weather sticks to you, and it doesn’t matter so much if you’re in the sun or not. The sun here has a different intensity, even when it’s not hot out.)

But 110 is hot, regardless the humidity.

During wet summer, outside is miserable, instead of just plain hot.

As an aside, it’s generally understood that the label “hot” is saved for 100 degrees or hotter.

Here’s to hoping we get storms soon. We need the water.

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