Mosquito season in Anne Arundel County, MD: when it starts and ends
Mosquito months in Anne Arundel County
In a normal year mosquito season in Anne Arundel County, MD starts around March 26 and ends around November 13, about 33 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Anne Arundel County, and when
- Start tipping out standing water weekly by March 12.
- Book any yard treatment for late March, ahead of the July peak.
- Repellent can go away after November 13.
- 12 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to September, and check MD spray notices.
Anne Arundel County against the rest of MD
Anne Arundel County has the 4th longest season of 24 MD counties, at 232 days against 235 in Wicomico County and 175 in Garrett County. Its mean temperature is 58.5°F.
- Baltimore city: March 25 to November 15 (235 days, 18 WNV)
- St. Mary's County: March 26 to November 15 (234 days, 0 WNV)
- Talbot County: March 26 to November 13 (232 days, 2 WNV)
- Dorchester County: March 27 to November 14 (232 days, 0 WNV)
West Nile in Anne Arundel County
From 1999 to 2025, CDC ArboNET counted 66 human West Nile cases in Anne Arundel County (47 neuroinvasive) across 14 years. The worst was 2015 with 14; the latest was 2025.
Background: reading the West Nile counts; how the dates are worked out.