Mosquito season in Hancock County, IA: when it starts and ends
Mosquito months in Hancock County
In a normal year mosquito season in Hancock County, IA starts around April 26 and ends around October 12, about 24 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Hancock County, and when
- Start tipping out standing water weekly by April 12.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 12.
- 1 West Nile case since 2016 (last 2022): you should use repellent at dusk July to July, more so if over 60.
Hancock County against the rest of IA
Hancock County has the 89th longest season of 99 IA counties, at 169 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 45.5°F.
- Kossuth County: April 26 to October 12 (170 days, 3 WNV)
- Cerro Gordo County: April 25 to October 11 (169 days, 0 WNV)
- Mitchell County: April 26 to October 11 (168 days, 1 WNV)
- Winnebago County: April 26 to October 11 (168 days, 0 WNV)
West Nile in Hancock County
From 1999 to 2025, CDC ArboNET counted 3 human West Nile cases in Hancock County (1 neuroinvasive) across 3 years. The worst was 2022 with 1; the latest was 2022.
Background: when the season starts across the US; how the dates are worked out.