Mosquito season in Shenandoah County, VA: when it starts and ends

Mosquito months in Shenandoah County

In a normal year mosquito season in Shenandoah County, VA starts around April 13 and ends around October 27, about 28 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 Shenandoah County, and when

• Start tipping out standing water weekly by March 30.
• Book any yard treatment for mid April, ahead of the July peak.
• Repellent can go away after October 27.
• 4 West Nile cases since 2016 (last 2025): you should use repellent at dusk July to August, more so if over 60.

Shenandoah County against the rest of VA

Shenandoah County has the 120th longest season of 133 VA counties, at 197 days against 257 in Norfolk city and 172 in Highland County. Its mean temperature is 52.8°F.

• Roanoke County: April 11 to October 26 (198 days, 1 WNV)
• Page County: April 13 to October 28 (198 days, 0 WNV)
• Alleghany County: April 14 to October 27 (196 days, 0 WNV)
• Covington city: April 14 to October 27 (196 days, 0 WNV)

West Nile in Shenandoah County

From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Shenandoah County (2 neuroinvasive) across 2 years. The worst was 2025 with 3; the latest was 2025.

See how the dates are worked out, and reading the West Nile counts.