Mosquito season in Clay County, FL: when it starts and ends

Mosquito months in Clay County

In a normal year mosquito season in Clay County, FL starts around January 23 and ends around January 4, about 49 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 Clay County, and when

• Start tipping out standing water weekly by January 9.
• Book any yard treatment for late January, ahead of the July peak.
• Repellent can go away after January 4.
• 3 West Nile cases since 2016 (last 2025): you should use repellent at dusk May to October, more so if over 60.

Clay County against the rest of FL

Clay County has the 33rd longest season of 67 FL counties, at 346 days against 365 in Broward County and 281 in Gilchrist County. Its mean temperature is 70.5°F.

• Bay County: January 23 to January 5 (347 days, 10 WNV)
• Bradford County: January 23 to January 4 (346 days, 0 WNV)
• Union County: January 23 to January 4 (346 days, 0 WNV)
• Volusia County: January 31 to January 10 (344 days, 3 WNV)

West Nile in Clay County

From 1999 to 2025, CDC ArboNET counted 7 human West Nile cases in Clay County (6 neuroinvasive) across 6 years. The worst was 2018 with 2; the latest was 2025.

Background: where mosquitoes never stop; how the dates are worked out.