Mosquito season in Harrison County, IN: when it starts and ends
Mosquito months in Harrison County
In a normal year mosquito season in Harrison County, IN starts around April 6 and ends around November 2, about 30 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Harrison County, and when
- Start tipping out standing water weekly by March 23.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after November 2.
- No West Nile cases since 2016, so bites in Harrison County are a nuisance; check window screens.
Harrison County against the rest of IN
Harrison County has the 20th longest season of 92 IN counties, at 210 days against 231 in Floyd County and 177 in Steuben County. Its mean temperature is 56.9°F.
- Crawford County: April 3 to October 31 (211 days, 1 WNV)
- Washington County: April 4 to November 1 (211 days, 0 WNV)
- Clay County: April 3 to October 29 (209 days, 1 WNV)
- Bartholomew County: April 4 to October 30 (209 days, 4 WNV)
West Nile in Harrison County
CDC ArboNET lists no human West Nile cases for Harrison County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 14 of those years.
More: how the dates are worked out · when the season starts across the US.