Mosquito season in Greene County, IL: when it starts and ends
Mosquito months in Greene County
In a normal year mosquito season in Greene County, IL starts around April 7 and ends around October 28, about 29 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Greene County, and when
- Start tipping out standing water weekly by March 24.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 28.
- No West Nile cases since 2016, so bites in Greene County are a nuisance; check window screens.
Greene County against the rest of IL
Greene County has the 48th longest season of 102 IL counties, at 204 days against 232 in Pulaski County and 174 in Boone County. Its mean temperature is 53°F.
- Moultrie County: April 6 to October 28 (205 days, 0 WNV)
- Adams County: April 6 to October 27 (204 days, 4 WNV)
- Sangamon County: April 7 to October 28 (204 days, 8 WNV)
- Scott County: April 7 to October 27 (203 days, 1 WNV)
West Nile in Greene County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Greene County (0 neuroinvasive) across 1 year. The worst was 2013 with 1; the latest was 2013.
See how the dates are worked out, and when the season starts across the US.