Mosquito season in Grayson County, TX: when it starts and ends
Mosquito months in Grayson County
In a normal year mosquito season in Grayson County, TX starts around March 2 and ends around November 28, about 39 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Grayson County, and when
- Start tipping out standing water weekly by February 16.
- Book any yard treatment for early March, ahead of the July peak.
- Repellent can go away after November 28.
- 18 West Nile cases since 2016: you should wear EPA-registered repellent at dusk May to September, and check TX spray notices.
Grayson County against the rest of TX
Grayson County has the 108th longest season of 254 TX counties, at 271 days against 365 in Cameron County and 191 in Lipscomb County. Its mean temperature is 63.6°F.
- Uvalde County: March 1 to November 27 (271 days, 1 WNV)
- Bosque County: March 2 to November 28 (271 days, 2 WNV)
- Hopkins County: March 2 to November 28 (271 days, 4 WNV)
- Ellis County: March 3 to November 29 (271 days, 10 WNV)
West Nile in Grayson County
From 1999 to 2025, CDC ArboNET counted 32 human West Nile cases in Grayson County (21 neuroinvasive) across 8 years. The worst was 2012 with 12; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.