Mosquito season in Hampshire County, MA: when it starts and ends
Mosquito months in Hampshire County
In a normal year mosquito season in Hampshire County, MA starts around April 24 and ends around October 16, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Hampshire County, and when
- Start tipping out standing water weekly by April 10.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 16.
- 2 West Nile cases since 2016 (last 2018): you should use repellent at dusk July to August, more so if over 60.
Hampshire County against the rest of MA
Hampshire County has the 10th longest season of 14 MA counties, at 175 days against 194 in Plymouth County and 163 in Berkshire County. Its mean temperature is 48.2°F.
- Dukes County: April 27 to October 25 (181 days, 0 WNV)
- Middlesex County: April 21 to October 18 (180 days, 65 WNV)
- Franklin County: April 25 to October 16 (174 days, 2 WNV)
- Essex County: April 28 to October 19 (174 days, 14 WNV)
West Nile in Hampshire County
From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Hampshire County (2 neuroinvasive) across 1 year. The worst was 2018 with 2; the latest was 2018.
More: how the dates are worked out · when the season starts across the US.