Mosquito season in Collin County, TX: when it starts and ends
Mosquito months in Collin County
In a normal year mosquito season in Collin County, TX starts around March 4 and ends around November 30, about 39 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Collin County, and when
- Start tipping out standing water weekly by February 18.
- Book any yard treatment for early March, ahead of the July peak.
- Repellent can go away after November 30.
- 62 West Nile cases since 2016: you should wear EPA-registered repellent at dusk May to September, and check TX spray notices.
Collin County against the rest of TX
Collin County has the 111th longest season of 254 TX counties, at 271 days against 365 in Cameron County and 191 in Lipscomb County. Its mean temperature is 64.9°F.
- Hopkins County: March 2 to November 28 (271 days, 4 WNV)
- Ellis County: March 3 to November 29 (271 days, 10 WNV)
- Kendall County: March 2 to November 27 (270 days, 1 WNV)
- Crane County: March 1 to November 25 (269 days, 0 WNV)
West Nile in Collin County
From 1999 to 2025, CDC ArboNET counted 174 human West Nile cases in Collin County (94 neuroinvasive) across 18 years. The worst was 2012 with 64; the latest was 2025.
See how the dates are worked out, and reading the West Nile counts.