Mosquito season in Charleston County, SC: when it starts and ends

Mosquito months in Charleston County

In a normal year mosquito season in Charleston County, SC starts around January 24 and ends around January 8, about 50 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 Charleston County, and when

• Start tipping out standing water weekly by January 10.
• Book any yard treatment for late January, ahead of the July peak.
• Repellent can go away after January 8.
• 11 West Nile cases since 2016: you should wear EPA-registered repellent at dusk May to September, and check SC spray notices.

Charleston County against the rest of SC

Charleston County has the 1st longest season of 46 SC counties, at 349 days against 349 in Charleston County and 209 in Cherokee County. Its mean temperature is 67.1°F.

• Jasper County: February 8 to January 12 (338 days, 0 WNV)
• Beaufort County: February 9 to December 28 (322 days, 3 WNV)

West Nile in Charleston County

From 1999 to 2025, CDC ArboNET counted 17 human West Nile cases in Charleston County (14 neuroinvasive) across 8 years. The worst was 2024 with 7; the latest was 2024.

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