Mosquito season in Addison County, VT: when it starts and ends
Mosquito months in Addison County
In a normal year mosquito season in Addison County, VT starts around April 30 and ends around October 11, about 23 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Addison County, and when
- Start tipping out standing water weekly by April 16.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 11.
- 1 West Nile case since 2016 (last 2017): you should use repellent at dusk July to July, more so if over 60.
Addison County against the rest of VT
Addison County has the 3rd longest season of 14 VT counties, at 164 days against 171 in Chittenden County and 144 in Orleans County. Its mean temperature is 45.4°F.
- Chittenden County: April 27 to October 14 (171 days, 2 WNV)
- Grand Isle County: April 27 to October 15 (171 days, 2 WNV)
- Franklin County: May 4 to October 10 (159 days, 0 WNV)
- Windsor County: May 3 to October 8 (158 days, 2 WNV)
West Nile in Addison County
From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Addison County (2 neuroinvasive) across 3 years. The worst was 2003 with 2; the latest was 2017.
More: how the dates are worked out · when mosquitoes go away for the winter.