Mosquito season in Portsmouth city, VA: when it starts and ends
Mosquito months in Portsmouth city
In a normal year mosquito season in Portsmouth city, VA starts around March 15 and ends around November 25, about 36 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Portsmouth city, and when
- Start tipping out standing water weekly by March 1.
- Book any yard treatment for mid March, ahead of the July peak.
- Repellent can go away after November 25.
- No West Nile cases since 2016, so bites in Portsmouth city are a nuisance; check window screens.
Portsmouth city against the rest of VA
Portsmouth city has the 2nd longest season of 133 VA counties, at 255 days against 257 in Norfolk city and 172 in Highland County. Its mean temperature is 60.9°F.
- Norfolk city: March 15 to November 26 (257 days, 7 WNV)
- Chesapeake city: March 17 to November 22 (250 days, 4 WNV)
- Hampton city: March 17 to November 22 (250 days, 3 WNV)
West Nile in Portsmouth city
From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Portsmouth city (3 neuroinvasive) across 3 years. The worst was 2015 with 2; the latest was 2015.
More: how the dates are worked out · when the season starts across the US.