Mosquito season in Lucas County, IA: when it starts and ends
Mosquito months in Lucas County
In a normal year mosquito season in Lucas County, IA starts around April 26 and ends around October 16, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Lucas 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 16.
- 1 West Nile case since 2016 (last 2025): you should use repellent at dusk July to August, more so if over 60.
Lucas County against the rest of IA
Lucas County has the 81st longest season of 99 IA counties, at 173 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 48.4°F.
- Webster County: April 23 to October 14 (173 days, 1 WNV)
- Cherokee County: April 24 to October 14 (173 days, 3 WNV)
- Delaware County: April 24 to October 13 (172 days, 0 WNV)
- Dickinson County: April 24 to October 13 (172 days, 1 WNV)
West Nile in Lucas County
From 1999 to 2025, CDC ArboNET counted 3 human West Nile cases in Lucas County (1 neuroinvasive) across 3 years. The worst was 2025 with 1; the latest was 2025.
Background: when mosquitoes go away for the winter; how the dates are worked out.