Mosquito season in Aroostook County, ME: when it starts and ends

Mosquito months in Aroostook County

In a normal year mosquito season in Aroostook County, ME starts around May 11 and ends around October 1, about 20 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 Aroostook County, and when

• Start tipping out standing water weekly by April 27.
• Book any yard treatment for mid May, ahead of the July peak.
• Repellent can go away after October 1.
• No West Nile cases since 2016, so bites in Aroostook County are a nuisance; check window screens.

Aroostook County against the rest of ME

Aroostook County has the 13th longest season of 16 ME counties, at 142 days against 164 in Kennebec County and 133 in Franklin County. Its mean temperature is 40.1°F.

• Penobscot County: May 8 to October 5 (150 days, 0 WNV)
• Oxford County: May 8 to October 4 (149 days, 0 WNV)
• Piscataquis County: May 14 to September 30 (139 days, 0 WNV)
• Somerset County: May 15 to September 29 (138 days, 0 WNV)

West Nile in Aroostook County

CDC ArboNET lists no human West Nile cases for Aroostook County from 1999 to 2025.

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