Mosquito season in Dickinson County, IA: when it starts and ends
Mosquito months in Dickinson County
In a normal year mosquito season in Dickinson County, IA starts around April 24 and ends around October 13, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Dickinson County, and when
- Start tipping out standing water weekly by April 10.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 13.
- 1 West Nile case since 2016 (last 2025): you should use repellent at dusk July to August, more so if over 60.
Dickinson County against the rest of IA
Dickinson County has the 83rd longest season of 99 IA counties, at 172 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 46°F.
- Lucas County: April 26 to October 16 (173 days, 1 WNV)
- Delaware County: April 24 to October 13 (172 days, 0 WNV)
- Hamilton County: April 24 to October 12 (171 days, 0 WNV)
- Benton County: April 25 to October 12 (170 days, 0 WNV)
West Nile in Dickinson County
From 1999 to 2025, CDC ArboNET counted 15 human West Nile cases in Dickinson County (7 neuroinvasive) across 7 years. The worst was 2003 with 5; the latest was 2025.
See how the dates are worked out, and when mosquitoes go away for the winter.