It’s a question we get in the weather center every summer: “Why does it become so much windier at night?”
Here’s the short, simple answer: After sunset, temperatures drop quickly, causing the winds to pick up.
Now, here’s the long answer:
You don’t need me to tell you that it gets so hot in the afternoons during the summertime. But during the afternoon, temperatures don’t really change all that much. You may have a 5 to 10 degree temperature increase from noon to the peak heat of the day at 5/6 p.m.. Winds are usually the calmest during the peak heat of the afternoon.
In contrast, at night, we experience a pretty drastic temperature drop after sunset and through the night. Temperatures will fall some 20 to 30 degrees from the afternoon high to the overnight low.
After the sun sets, leftover warm air from the day at the surface rises and cooler air from high up in the atmosphere sinks to the surface. This process is called atmospheric mixing.
The gusty winds we feel at night are the direct result of the mixing: rising of the warm air and sinking of the cooler air to the surface.
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