Mosquito season in Lewis County, NY: when it starts and ends
Mosquito months in Lewis County
In a normal year mosquito season in Lewis County, NY starts around May 4 and ends around October 7, about 22 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Lewis 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 7.
- No West Nile cases since 2016, so bites in Lewis County are a nuisance; check window screens.
Lewis County against the rest of NY
Lewis County has the 53rd longest season of 62 NY counties, at 156 days against 218 in New York County and 125 in Franklin County. Its mean temperature is 43.7°F.
- Delaware County: May 5 to October 10 (158 days, 0 WNV)
- Wyoming County: May 5 to October 9 (157 days, 2 WNV)
- Washington County: May 5 to October 7 (155 days, 1 WNV)
- Otsego County: May 6 to October 6 (154 days, 0 WNV)
West Nile in Lewis County
CDC ArboNET lists no human West Nile cases for Lewis County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 10 of those years.
More: how the dates are worked out · when the season starts across the US.