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

Mosquito months in Horry County

In a normal year mosquito season in Horry County, SC starts around February 28 and ends around December 7, about 40 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 Horry County, and when

• Start tipping out standing water weekly by February 14.
• Book any yard treatment for late February, ahead of the July peak.
• Repellent can go away after December 7.
• 11 West Nile cases since 2016: you should wear EPA-registered repellent at dusk May to September, and check SC spray notices.

Horry County against the rest of SC

Horry County has the 9th longest season of 46 SC counties, at 282 days against 349 in Charleston County and 209 in Cherokee County. Its mean temperature is 64.1°F.

• Richland County: February 24 to December 4 (283 days, 10 WNV)
• Calhoun County: February 23 to December 2 (282 days, 0 WNV)
• Orangeburg County: February 28 to December 6 (281 days, 0 WNV)
• Edgefield County: February 28 to December 1 (276 days, 0 WNV)

West Nile in Horry County

From 1999 to 2025, CDC ArboNET counted 13 human West Nile cases in Horry County (12 neuroinvasive) across 8 years. The worst was 2024 with 3; the latest was 2024.

More: how the dates are worked out · reading the West Nile counts.