Mosquito season in Alexandria city, VA: when it starts and ends

Mosquito months in Alexandria city

In a normal year mosquito season in Alexandria city, VA starts around March 26 and ends around November 10, about 33 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 Alexandria city, 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 10.
• 8 West Nile cases since 2016 (last 2025): you should use repellent at dusk June to September, more so if over 60.

Alexandria city against the rest of VA

Alexandria city has the 35th longest season of 133 VA counties, at 229 days against 257 in Norfolk city and 172 in Highland County. Its mean temperature is 57.7°F.

• Amelia County: March 26 to November 12 (231 days, 0 WNV)
• Roanoke city: March 24 to November 8 (229 days, 6 WNV)
• King and Queen County: March 27 to November 11 (229 days, 0 WNV)
• King William County: March 27 to November 11 (229 days, 0 WNV)

West Nile in Alexandria city

From 1999 to 2025, CDC ArboNET counted 18 human West Nile cases in Alexandria city (13 neuroinvasive) across 13 years. The worst was 2025 with 3; the latest was 2025.

More: how the dates are worked out · reading the West Nile counts.