Mosquito season in Humboldt County, IA: when it starts and ends
Mosquito months in Humboldt County
In a normal year mosquito season in Humboldt County, IA starts around April 23 and ends around October 15, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Humboldt County, and when
- Start tipping out standing water weekly by April 9.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 15.
- 3 West Nile cases since 2016 (last 2018): you should use repellent at dusk July to August, more so if over 60.
Humboldt County against the rest of IA
Humboldt County has the 72nd longest season of 99 IA counties, at 175 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 46.5°F.
- Guthrie County: April 23 to October 15 (175 days, 1 WNV)
- Hardin County: April 23 to October 15 (175 days, 2 WNV)
- Floyd County: April 22 to October 14 (174 days, 1 WNV)
- Bremer County: April 23 to October 14 (174 days, 4 WNV)
West Nile in Humboldt County
From 1999 to 2025, CDC ArboNET counted 7 human West Nile cases in Humboldt County (2 neuroinvasive) across 5 years. The worst was 2018 with 2; the latest was 2018.
Background: when the season starts across the US; how the dates are worked out.