Mosquito season in Cortland County, NY: when it starts and ends
Mosquito months in Cortland County
In a normal year mosquito season in Cortland County, NY starts around May 4 and ends around October 9, about 23 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Cortland County, and when
- Start tipping out standing water weekly by April 20.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 9.
- No West Nile cases since 2016, so bites in Cortland County are a nuisance; check window screens.
Cortland County against the rest of NY
Cortland County has the 50th longest season of 62 NY counties, at 158 days against 218 in New York County and 125 in Franklin County. Its mean temperature is 44.9°F.
- Cattaraugus County: May 3 to October 10 (160 days, 1 WNV)
- Madison County: May 3 to October 9 (159 days, 0 WNV)
- Delaware County: May 5 to October 10 (158 days, 0 WNV)
- Wyoming County: May 5 to October 9 (157 days, 2 WNV)
West Nile in Cortland County
CDC ArboNET lists no human West Nile cases for Cortland County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 7 of those years.
More: how the dates are worked out · when mosquitoes go away for the winter.