Mosquito season in Henrico County, VA: when it starts and ends
Mosquito months in Henrico County
In a normal year mosquito season in Henrico County, VA starts around March 22 and ends around November 13, about 34 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Henrico County, and when
- Start tipping out standing water weekly by March 8.
- Book any yard treatment for late March, ahead of the July peak.
- Repellent can go away after November 13.
- 6 West Nile cases since 2016 (last 2025): you should use repellent at dusk June to September, more so if over 60.
Henrico County against the rest of VA
Henrico County has the 22nd longest season of 133 VA counties, at 236 days against 257 in Norfolk city and 172 in Highland County. Its mean temperature is 58.9°F.
- Northampton County: March 26 to November 19 (238 days, 0 WNV)
- Accomack County: March 25 to November 17 (237 days, 0 WNV)
- Middlesex County: March 23 to November 14 (236 days, 0 WNV)
- Richmond city: March 23 to November 11 (234 days, 6 WNV)
West Nile in Henrico County
From 1999 to 2025, CDC ArboNET counted 9 human West Nile cases in Henrico County (8 neuroinvasive) across 6 years. The worst was 2018 with 3; the latest was 2025.
Background: reading the West Nile counts; how the dates are worked out.