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

Mosquito months in Franklin County

In a normal year mosquito season in Franklin County, ME starts around May 17 and ends around September 27, about 19 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 Franklin County, and when

• Start tipping out standing water weekly by May 3.
• Book any yard treatment for mid May, ahead of the July peak.
• Repellent can go away after September 27.
• No West Nile cases since 2016, so bites in Franklin County are a nuisance; check window screens.

Franklin County against the rest of ME

Franklin County has the 16th longest season of 16 ME counties, at 133 days against 164 in Kennebec County and 133 in Franklin County. Its mean temperature is 39°F.

• 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 Franklin County

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

More: how the dates are worked out · when the season starts across the US.