Mosquito season in Hays County, TX: when it starts and ends
Mosquito months in Hays County
In a normal year mosquito season in Hays County, TX starts around March 4 and ends around November 26, about 38 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Hays County, and when
- Start tipping out standing water weekly by February 18.
- Book any yard treatment for early March, ahead of the August peak.
- Repellent can go away after November 26.
- 6 West Nile cases since 2016 (last 2025): you should use repellent at dusk May to September, more so if over 60.
Hays County against the rest of TX
Hays County has the 121st longest season of 254 TX counties, at 267 days against 365 in Cameron County and 191 in Lipscomb County. Its mean temperature is 67.8°F.
- McCulloch County: March 4 to November 27 (268 days, 0 WNV)
- Freestone County: March 4 to November 26 (267 days, 3 WNV)
- Mason County: March 4 to November 26 (267 days, 0 WNV)
- Andrews County: March 4 to November 25 (266 days, 0 WNV)
West Nile in Hays County
From 1999 to 2025, CDC ArboNET counted 13 human West Nile cases in Hays County (8 neuroinvasive) across 4 years. The worst was 2012 with 6; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.