Mosquito season in Jefferson County, FL: when it starts and ends
Mosquito months in Jefferson County
In a normal year mosquito season in Jefferson County, FL starts around February 4 and ends around December 27, about 47 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Jefferson County, and when
- Start tipping out standing water weekly by January 21.
- Book any yard treatment for early February, ahead of the July peak.
- Repellent can go away after December 27.
- No West Nile cases since 2016, so bites in Jefferson County are a nuisance; check window screens.
Jefferson County against the rest of FL
Jefferson County has the 43rd longest season of 67 FL counties, at 326 days against 365 in Broward County and 281 in Gilchrist County. Its mean temperature is 67.5°F.
- Nassau County: February 4 to January 2 (332 days, 4 WNV)
- Franklin County: February 5 to January 1 (330 days, 0 WNV)
- Pasco County: February 7 to December 29 (325 days, 1 WNV)
- Levy County: February 6 to December 27 (324 days, 1 WNV)
West Nile in Jefferson County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Jefferson County (1 neuroinvasive) across 1 year. The worst was 2001 with 1; the latest was 2001.
More: how the dates are worked out · when mosquitoes go away for the winter.