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

Mosquito months in Tom Green County

In a normal year mosquito season in Tom Green County, TX starts around March 6 and ends around November 22, about 37 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 Tom Green County, and when

• Start tipping out standing water weekly by February 20.
• Book any yard treatment for early March, ahead of the July peak.
• Repellent can go away after November 22.
• 5 West Nile cases since 2016 (last 2025): you should use repellent at dusk May to September, more so if over 60.

Tom Green County against the rest of TX

Tom Green County has the 147th longest season of 254 TX counties, at 261 days against 365 in Cameron County and 191 in Lipscomb County. Its mean temperature is 66.1°F.

• Llano County: March 5 to November 21 (261 days, 0 WNV)
• Blanco County: March 6 to November 22 (261 days, 1 WNV)
• Coryell County: March 5 to November 20 (260 days, 0 WNV)
• Brown County: March 7 to November 21 (259 days, 2 WNV)

West Nile in Tom Green County

From 1999 to 2025, CDC ArboNET counted 27 human West Nile cases in Tom Green County (15 neuroinvasive) across 11 years. The worst was 2012 with 13; the latest was 2025.

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