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

Mosquito months in Oconee County

In a normal year mosquito season in Oconee County, SC starts around March 30 and ends around November 9, about 32 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 Oconee County, and when

• Start tipping out standing water weekly by March 16.
• Book any yard treatment for late March, ahead of the July peak.
• Repellent can go away after November 9.
• No West Nile cases since 2016, so bites in Oconee County are a nuisance; check window screens.

Oconee County against the rest of SC

Oconee County has the 45th longest season of 46 SC counties, at 224 days against 349 in Charleston County and 209 in Cherokee County. Its mean temperature is 59.3°F.

• Spartanburg County: March 24 to November 11 (232 days, 4 WNV)
• Union County: March 24 to November 10 (231 days, 2 WNV)
• Cherokee County: April 6 to November 1 (209 days, 1 WNV)

West Nile in Oconee County

From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Oconee County (3 neuroinvasive) across 3 years. The worst was 2012 with 2; the latest was 2013.

Background: when the season starts across the US; how the dates are worked out.