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

Mosquito months in Hillsborough County

Mosquitoes in Hillsborough County, FL can be active in any month. The worst stretch is April to October.

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 Hillsborough County, and when

• No off-season here: tip out standing water every week, all year.
• A yard treatment matters most April to October.
• 2 West Nile cases since 2016 (last 2024): you should use repellent at dusk April to October, more so if over 60.

Hillsborough County against the rest of FL

Hillsborough County has the 4th longest season of 67 FL counties, at 365 days against 365 in Broward County and 281 in Gilchrist County. Its mean temperature is 74.1°F.

• Charlotte County: all year (365 days, 2 WNV)
• Collier County: all year (365 days, 11 WNV)
• Indian River County: all year (365 days, 0 WNV)
• Lee County: all year (365 days, 1 WNV)

West Nile in Hillsborough County

From 1999 to 2025, CDC ArboNET counted 10 human West Nile cases in Hillsborough County (9 neuroinvasive) across 7 years. The worst was 2004 with 3; the latest was 2024.

See how the dates are worked out, and where mosquitoes never stop.