Mosquito season in Barnstable County, MA: when it starts and ends
Mosquito months in Barnstable County
In a normal year mosquito season in Barnstable County, MA starts around April 28 and ends around October 29, about 26 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Barnstable County, and when
- Start tipping out standing water weekly by April 14.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 29.
- 7 West Nile cases since 2016 (last 2024): you should use repellent at dusk July to August, more so if over 60.
Barnstable County against the rest of MA
Barnstable County has the 6th longest season of 14 MA counties, at 184 days against 194 in Plymouth County and 163 in Berkshire County. Its mean temperature is 50.7°F.
- Nantucket County: May 1 to November 2 (185 days, 0 WNV)
- Bristol County: April 23 to October 24 (184 days, 8 WNV)
- Hampden County: April 21 to October 19 (181 days, 7 WNV)
- Dukes County: April 27 to October 25 (181 days, 0 WNV)
West Nile in Barnstable County
From 1999 to 2025, CDC ArboNET counted 8 human West Nile cases in Barnstable County (6 neuroinvasive) across 4 years. The worst was 2018 with 4; the latest was 2024.
More: how the dates are worked out · reading the West Nile counts.