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

Mosquito months in Denton County

In a normal year mosquito season in Denton County, TX starts around March 1 and ends around December 1, about 39 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 Denton County, and when

• Start tipping out standing water weekly by February 15.
• Book any yard treatment for early March, ahead of the July peak.
• Repellent can go away after December 1.
• 81 West Nile cases since 2016: you should wear EPA-registered repellent at dusk May to September, and check TX spray notices.

Denton County against the rest of TX

Denton County has the 98th longest season of 254 TX counties, at 275 days against 365 in Cameron County and 191 in Lipscomb County. Its mean temperature is 65.3°F.

• Bell County: March 1 to December 1 (275 days, 12 WNV)
• Coleman County: March 1 to December 1 (275 days, 0 WNV)
• Lamar County: March 1 to December 1 (275 days, 3 WNV)
• Franklin County: March 2 to December 1 (274 days, 3 WNV)

West Nile in Denton County

From 1999 to 2025, CDC ArboNET counted 320 human West Nile cases in Denton County (141 neuroinvasive) across 19 years. The worst was 2012 with 183; the latest was 2025.

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