When do mosquitoes go away?

“The bites have finally slowed down. When do mosquitoes normally die off?”

In most of the western U.S., mosquitoes start to fade once nighttime temperatures drop below 50°F, and the majority of adults die after the first hard frost. "Die off" is a bit misleading, though, as some mosquitoes don't actually die in the fall; they hide, to wait out the cold and come back the moment temperatures climb again. Plus, many lay eggs to prepare for next year’s mosquito season.

And if you live in warmer parts of California, Arizona, or southern Nevada, mosquitoes can stay active well into winter, especially around standing water or irrigated yards.

The temperature at which mosquitoes die off

Mosquitoes need warmth to fly, feed, and breed. Here are some of the key temperatures that affect mosquito behavior and lifespan.

• Below 80°F: breeding slows
• Below 60°F: flight activity drops noticeably
• Below 50°F: most adults stop flying
• Below 28°F for two hours or more: a frost finishes off most exposed adults

Eggs and overwintering females can survive in sheltered spots like sheds, culverts, hollow logs, and warm crawl spaces. Once spring temperatures climb back into the 60s and 70s, those eggs hatch and the cycle starts over.

A few simple steps can help cut down on next year's mosquito population. Remember to empty buckets, planters, gutters, and bird baths weekly over the winter and clear damp leaf piles where adults shelter. Contact our mosquito control team to ask about mosquito prevention plans.