Mosquito season in Saline County, IL: when it starts and ends
Mosquito months in Saline County
In a normal year mosquito season in Saline County, IL starts around March 26 and ends around November 6, about 32 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Saline County, and when
- Start tipping out standing water weekly by March 12.
- Book any yard treatment for late March, ahead of the July peak.
- Repellent can go away after November 6.
- No West Nile cases since 2016, so bites in Saline County are a nuisance; check window screens.
Saline County against the rest of IL
Saline County has the 2nd longest season of 102 IL counties, at 225 days against 232 in Pulaski County and 174 in Boone County. Its mean temperature is 57.3°F.
- Pulaski County: March 23 to November 10 (232 days, 0 WNV)
- Gallatin County: March 26 to November 5 (224 days, 0 WNV)
- Madison County: March 27 to November 6 (224 days, 9 WNV)
West Nile in Saline County
From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Saline County (2 neuroinvasive) across 2 years. The worst was 2007 with 3; the latest was 2007.
See how the dates are worked out, and when the season starts across the US.