Mosquito season in Columbia County, NY: when it starts and ends
Mosquito months in Columbia County
In a normal year mosquito season in Columbia County, NY starts around April 22 and ends around October 18, about 26 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Columbia County, and when
- Start tipping out standing water weekly by April 8.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 18.
- 2 West Nile cases since 2016 (last 2022): you should use repellent at dusk July to August, more so if over 60.
Columbia County against the rest of NY
Columbia County has the 15th longest season of 62 NY counties, at 179 days against 218 in New York County and 125 in Franklin County. Its mean temperature is 49°F.
- Chautauqua County: April 23 to October 23 (183 days, 0 WNV)
- Orleans County: April 24 to October 21 (180 days, 1 WNV)
- Monroe County: April 25 to October 20 (179 days, 13 WNV)
- Dutchess County: April 22 to October 17 (177 days, 8 WNV)
West Nile in Columbia County
From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Columbia County (2 neuroinvasive) across 2 years. The worst was 2022 with 1; the latest was 2022.
Background: when the season starts across the US; how the dates are worked out.