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

Mosquito months in Duval County

In a normal year mosquito season in Duval County, FL starts around January 22 and ends around January 14, about 51 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 Duval County, and when

• Start tipping out standing water weekly by January 8.
• Book any yard treatment for late January, ahead of the July peak.
• Repellent can go away after January 14.
• 20 West Nile cases since 2016: you should wear EPA-registered repellent at dusk May to October, and check FL spray notices.

Duval County against the rest of FL

Duval County has the 24th longest season of 67 FL counties, at 357 days against 365 in Broward County and 281 in Gilchrist County. Its mean temperature is 70.3°F.

• Sarasota County: January 15 to January 9 (359 days, 2 WNV)
• Hendry County: January 20 to January 14 (359 days, 0 WNV)
• Putnam County: January 21 to January 12 (356 days, 2 WNV)
• Okeechobee County: January 22 to January 13 (356 days, 1 WNV)

West Nile in Duval County

From 1999 to 2025, CDC ArboNET counted 89 human West Nile cases in Duval County (70 neuroinvasive) across 17 years. The worst was 2012 with 28; the latest was 2025.

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