Mosquito season in Marion County, SC: when it starts and ends
Mosquito months in Marion County
In a normal year mosquito season in Marion County, SC starts around March 4 and ends around November 24, about 38 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Marion County, and when
- Start tipping out standing water weekly by February 18.
- Book any yard treatment for early March, ahead of the July peak.
- Repellent can go away after November 24.
- No West Nile cases since 2016, so bites in Marion County are a nuisance; check window screens.
Marion County against the rest of SC
Marion County has the 19th longest season of 46 SC counties, at 265 days against 349 in Charleston County and 209 in Cherokee County. Its mean temperature is 62.9°F.
- Florence County: March 4 to November 27 (268 days, 5 WNV)
- Dorchester County: March 7 to November 29 (267 days, 4 WNV)
- Kershaw County: March 11 to November 27 (261 days, 1 WNV)
- Clarendon County: March 9 to November 24 (260 days, 0 WNV)
West Nile in Marion County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Marion County (1 neuroinvasive) across 1 year. The worst was 2012 with 1; the latest was 2012.
More: how the dates are worked out · when mosquitoes go away for the winter.