Mosquito season in Jay County, IN: when it starts and ends
Mosquito months in Jay County
In a normal year mosquito season in Jay County, IN starts around April 16 and ends around October 22, about 27 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Jay County, and when
- Start tipping out standing water weekly by April 2.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 22.
- 2 West Nile cases since 2016 (last 2025): you should use repellent at dusk July to August, more so if over 60.
Jay County against the rest of IN
Jay County has the 74th longest season of 92 IN counties, at 189 days against 231 in Floyd County and 177 in Steuben County. Its mean temperature is 50.3°F.
- Grant County: April 16 to October 23 (190 days, 2 WNV)
- Jasper County: April 16 to October 22 (189 days, 2 WNV)
- Wells County: April 16 to October 22 (189 days, 2 WNV)
- Elkhart County: April 17 to October 22 (189 days, 8 WNV)
West Nile in Jay County
From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Jay County (2 neuroinvasive) across 3 years. The worst was 2002 with 2; the latest was 2025.
See how the dates are worked out, and when the season starts across the US.