Mosquito season in Clinton County, IA: when it starts and ends
Mosquito months in Clinton County
In a normal year mosquito season in Clinton County, IA starts around April 17 and ends around October 19, about 27 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Clinton County, and when
- Start tipping out standing water weekly by April 3.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 19.
- 3 West Nile cases since 2016 (last 2023): you should use repellent at dusk June to August, more so if over 60.
Clinton County against the rest of IA
Clinton County has the 29th longest season of 99 IA counties, at 186 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 49.1°F.
- Dallas County: April 16 to October 19 (186 days, 0 WNV)
- Adair County: April 17 to October 20 (186 days, 0 WNV)
- Henry County: April 17 to October 20 (186 days, 2 WNV)
- Shelby County: April 17 to October 19 (185 days, 3 WNV)
West Nile in Clinton County
From 1999 to 2025, CDC ArboNET counted 5 human West Nile cases in Clinton County (4 neuroinvasive) across 4 years. The worst was 2016 with 2; the latest was 2023.
See how the dates are worked out, and when the season starts across the US.