Mosquito season in Somerset County, MD: when it starts and ends

Mosquito months in Somerset County

In a normal year mosquito season in Somerset County, MD starts around March 27 and ends around November 13, about 33 weeks.

What to do in Somerset County, and when

Start tipping out standing water weekly by March 13.
Book any yard treatment for late March, ahead of the July peak.
Repellent can go away after November 13.
No West Nile cases since 2016, so bites in Somerset County are a nuisance; check window screens.

Somerset County against the rest of MD

Somerset County has the 7th longest season of 24 MD counties, at 231 days against 235 in Wicomico County and 175 in Garrett County. Its mean temperature is 57.8°F.

Talbot County: March 26 to November 13 (232 days, 2 WNV)
Dorchester County: March 27 to November 14 (232 days, 0 WNV)
Worcester County: March 29 to November 11 (227 days, 0 WNV)
Baltimore County: March 30 to November 9 (223 days, 26 WNV)

West Nile in Somerset County

CDC ArboNET lists no human West Nile cases for Somerset County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 3 of those years.

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