Mosquito season in St. Clair County, AL: when it starts and ends

Mosquito months in St. Clair County

In a normal year mosquito season in St. Clair County, AL starts around March 8 and ends around November 24, about 37 weeks.

What to do in St. Clair County, and when

Start tipping out standing water weekly by February 22.
Book any yard treatment for early March, ahead of the July peak.
Repellent can go away after November 24.
No West Nile cases since 2016, so bites in St. Clair County are a nuisance; check window screens.

St. Clair County against the rest of AL

St. Clair County has the 29th longest season of 67 AL counties, at 261 days against 330 in Montgomery County and 218 in Marion County. Its mean temperature is 62.1°F.

Fayette County: March 5 to November 22 (262 days, 1 WNV)
Jefferson County: March 7 to November 24 (262 days, 34 WNV)
Covington County: March 7 to November 22 (260 days, 1 WNV)
Geneva County: March 6 to November 20 (259 days, 0 WNV)

West Nile in St. Clair County

CDC ArboNET lists no human West Nile cases for St. Clair County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 3 of those years.

See how the dates are worked out, and when mosquitoes go away for the winter.