Mosquito season in Fayette County, IL: when it starts and ends
Mosquito months in Fayette County
In a normal year mosquito season in Fayette County, IL starts around April 2 and ends around October 30, about 30 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Fayette County, and when
- Start tipping out standing water weekly by March 19.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 30.
- No West Nile cases since 2016, so bites in Fayette County are a nuisance; check window screens.
Fayette County against the rest of IL
Fayette County has the 33rd longest season of 102 IL counties, at 210 days against 232 in Pulaski County and 174 in Boone County. Its mean temperature is 54.3°F.
- Effingham County: April 3 to October 31 (211 days, 1 WNV)
- Jasper County: April 3 to October 31 (211 days, 0 WNV)
- Richland County: April 3 to October 31 (210 days, 1 WNV)
- Crawford County: April 4 to October 30 (209 days, 0 WNV)
West Nile in Fayette County
From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Fayette County (2 neuroinvasive) across 1 year. The worst was 2015 with 2; the latest was 2015.
More: how the dates are worked out · when the season starts across the US.