Mosquito season in Niagara County, NY: when it starts and ends
Mosquito months in Niagara County
In a normal year mosquito season in Niagara County, NY starts around April 27 and ends around October 21, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Niagara County, and when
- Start tipping out standing water weekly by April 13.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 21.
- 5 West Nile cases since 2016 (last 2025): you should use repellent at dusk July to August, more so if over 60.
Niagara County against the rest of NY
Niagara County has the 19th longest season of 62 NY counties, at 176 days against 218 in New York County and 125 in Franklin County. Its mean temperature is 48.9°F.
- Dutchess County: April 22 to October 17 (177 days, 8 WNV)
- Yates County: April 26 to October 19 (176 days, 0 WNV)
- Ontario County: April 27 to October 20 (176 days, 1 WNV)
- Saratoga County: April 23 to October 16 (175 days, 3 WNV)
West Nile in Niagara County
From 1999 to 2025, CDC ArboNET counted 10 human West Nile cases in Niagara County (7 neuroinvasive) across 8 years. The worst was 2023 with 2; the latest was 2025.
Background: reading the West Nile counts; how the dates are worked out.