Mosquito season in Rensselaer County, NY: when it starts and ends

Mosquito months in Rensselaer County

In a normal year mosquito season in Rensselaer County, NY starts around April 29 and ends around October 12, about 24 weeks.

1. Jan
2. Feb
3. Mar
4. Apr
5. May
6. Jun
7. Jul
8. Aug
9. Sep
10. Oct
11. Nov
12. Dec

What to do in Rensselaer County, and when

• Start tipping out standing water weekly by April 15.
• Book any yard treatment for late April, ahead of the July peak.
• Repellent can go away after October 12.
• 1 West Nile case since 2016 (last 2018): you should use repellent at dusk July, more so if over 60.

Rensselaer County against the rest of NY

Rensselaer County has the 34th longest season of 62 NY counties, at 167 days against 218 in New York County and 125 in Franklin County. Its mean temperature is 46.1°F.

• Erie County: April 30 to October 15 (169 days, 12 WNV)
• Albany County: April 27 to October 12 (168 days, 4 WNV)
• Wayne County: April 30 to October 14 (167 days, 1 WNV)
• Schoharie County: April 30 to October 12 (165 days, 0 WNV)

West Nile in Rensselaer County

From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Rensselaer County (2 neuroinvasive) across 2 years. The worst was 2018 with 1; the latest was 2018.

Background: when the season starts across the US; how the dates are worked out.