Mosquito season in Terrell County, TX: when it starts and ends

Mosquito months in Terrell County

In a normal year mosquito season in Terrell County, TX starts around February 11 and ends around December 9, about 43 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 Terrell County, and when

• Start tipping out standing water weekly by January 28.
• Book any yard treatment for mid February, ahead of the July peak.
• Repellent can go away after December 9.
• No West Nile cases since 2016, so bites in Terrell County are a nuisance; check window screens.

Terrell County against the rest of TX

Terrell County has the 61st longest season of 254 TX counties, at 301 days against 365 in Cameron County and 191 in Lipscomb County. Its mean temperature is 67.4°F.

• Guadalupe County: February 4 to December 8 (307 days, 1 WNV)
• Atascosa County: February 10 to December 10 (303 days, 0 WNV)
• Polk County: February 14 to December 12 (301 days, 3 WNV)
• Medina County: February 12 to December 9 (300 days, 1 WNV)

West Nile in Terrell County

From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Terrell County (0 neuroinvasive) across 1 year. The worst was 2004 with 1; the latest was 2004.

Background: when mosquitoes go away for the winter; how the dates are worked out.