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

Mosquito months in Ellis County

In a normal year mosquito season in Ellis County, TX starts around March 3 and ends around November 29, 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 Ellis County, and when

• Start tipping out standing water weekly by February 17.
• Book any yard treatment for early March, ahead of the August peak.
• Repellent can go away after November 29.
• 10 West Nile cases since 2016: you should wear EPA-registered repellent at dusk May to September, and check TX spray notices.

Ellis County against the rest of TX

Ellis County has the 110th longest season of 254 TX counties, at 271 days against 365 in Cameron County and 191 in Lipscomb County. Its mean temperature is 65.5°F.

• Grayson County: March 2 to November 28 (271 days, 18 WNV)
• Hopkins County: March 2 to November 28 (271 days, 4 WNV)
• Collin County: March 4 to November 30 (271 days, 62 WNV)
• Kendall County: March 2 to November 27 (270 days, 1 WNV)

West Nile in Ellis County

From 1999 to 2025, CDC ArboNET counted 46 human West Nile cases in Ellis County (28 neuroinvasive) across 12 years. The worst was 2012 with 26; the latest was 2024.

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