Mosquito season in Delaware County, IN: when it starts and ends
Mosquito months in Delaware County
In a normal year mosquito season in Delaware County, IN starts around April 6 and ends around October 30, about 30 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Delaware 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 October 30.
- 6 West Nile cases since 2016 (last 2020): you should use repellent at dusk June to August, more so if over 60.
Delaware County against the rest of IN
Delaware County has the 25th longest season of 92 IN counties, at 207 days against 231 in Floyd County and 177 in Steuben County. Its mean temperature is 53.7°F.
- Scott County: April 5 to October 31 (209 days, 0 WNV)
- Decatur County: April 5 to October 29 (207 days, 0 WNV)
- Pike County: April 7 to October 31 (207 days, 0 WNV)
- Jackson County: April 5 to October 28 (206 days, 0 WNV)
West Nile in Delaware County
From 1999 to 2025, CDC ArboNET counted 18 human West Nile cases in Delaware County (13 neuroinvasive) across 9 years. The worst was 2003 with 4; the latest was 2020.
Background: reading the West Nile counts; how the dates are worked out.