Mosquito season estimator
Pick your region and a month to get an honest estimate of when mosquito season starts and ends near you — and whether they're active right now. This is a general guide, not a forecast.
Quick answer
Mosquito season roughly tracks frost: it ramps up a few weeks after your last spring frost and winds down at the first hard fall frost. In the Deep South it can run most of the year; in the Northeast and Mountain West it may be just four or five months. Adults need sustained warmth to fly and bite, so the exact dates shift with the weather every year.
Estimate your season
Select a region to see the estimate.
These windows are approximate climatology bands, not a prediction. A warm spring or a late frost can shift them by weeks. [VERIFY — approximate, not pinned to a cited climate dataset]
Approximate season windows by region
| Region | Approx. season | Typical peak |
|---|---|---|
| Deep South / Gulf Coast | February–November | May–September |
| Southeast | March–October | June–September |
| Southwest / Desert | March–November | July–September (monsoon) |
| Mid-Atlantic | April–October | June–September |
| Midwest | April/May–September | June–August |
| Pacific Northwest | May–September | June–August |
| Northeast | May–September | June–August |
| Mountain West / High Elevation | May–September | June–August |
Why mosquito season works this way
Mosquitoes are cold-blooded, so their activity is driven by temperature. As a rough rule, host-seeking females need sustained temperatures of around 50°F (10°C) or warmer to fly and bite; below that they slow down and stop. [VERIFY — ~50°F threshold is general entomological guidance, not pinned to our own sourced copy] That's why the season opens in spring as the air and standing water warm up, peaks through the hottest, most humid months, and fades as fall nights turn cold.
The bugs don't die out completely in winter — they wait it out. Many species overwinter as mated females sheltering in protected spots, while container species like the Asian tiger mosquito can survive the cold as desiccation-resistant, diapausing eggs that hatch when warm rain refloods them. So a mild winter or an early warm spell can wake a few biters well before the "real" season starts.
Activity also varies by species through the day, not just the season. Culex "house mosquitoes" bite mostly from dusk through the night, while daytime Aedes species are aggressive shade biters in the afternoon — which is why "mosquitoes only come out at dusk" is a myth. For the underlying biology, see the science of how mosquitoes find you and our guide to what actually kills mosquitoes in a backyard.
Stop guessing — run on the right windows automatically
SkeeterSwitch runs a CO₂ + heat trap on local weather and mosquito-activity windows, so it's working through your season without you watching a calendar.