Mosquito season in Adams County, IA: when it starts and ends
Mosquito months in Adams County
In a normal year mosquito season in Adams County, IA starts around April 18 and ends around October 19, about 26 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Adams County, and when
- Start tipping out standing water weekly by April 4.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 19.
- 2 West Nile cases since 2016 (last 2023): you should use repellent at dusk June to August, more so if over 60.
Adams County against the rest of IA
Adams County has the 33rd longest season of 99 IA counties, at 185 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 49.4°F.
- Shelby County: April 17 to October 19 (185 days, 3 WNV)
- Washington County: April 17 to October 19 (185 days, 1 WNV)
- Clarke County: April 18 to October 20 (185 days, 1 WNV)
- Keokuk County: April 18 to October 19 (184 days, 1 WNV)
West Nile in Adams County
From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Adams County (2 neuroinvasive) across 4 years. The worst was 2023 with 1; the latest was 2023.
See how the dates are worked out, and when mosquitoes go away for the winter.