Mosquito season in Fremont County, IA: when it starts and ends
Mosquito months in Fremont County
In a normal year mosquito season in Fremont County, IA starts around April 13 and ends around October 23, about 28 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Fremont County, and when
- Start tipping out standing water weekly by March 30.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 23.
- 1 West Nile case since 2016 (last 2016): you should use repellent at dusk June to August, more so if over 60.
Fremont County against the rest of IA
Fremont County has the 4th longest season of 99 IA counties, at 193 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 50.9°F.
- Lee County: April 10 to October 25 (198 days, 1 WNV)
- Davis County: April 12 to October 24 (195 days, 0 WNV)
- Wapello County: April 13 to October 22 (192 days, 0 WNV)
- Johnson County: April 13 to October 21 (191 days, 7 WNV)
West Nile in Fremont County
From 1999 to 2025, CDC ArboNET counted 5 human West Nile cases in Fremont County (3 neuroinvasive) across 5 years. The worst was 2016 with 1; the latest was 2016.
More: how the dates are worked out · when the season starts across the US.