Mosquito season in Sumter County, SC: when it starts and ends
Mosquito months in Sumter County
In a normal year mosquito season in Sumter County, SC starts around March 13 and ends around November 21, about 36 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Sumter County, and when
- Start tipping out standing water weekly by February 27.
- Book any yard treatment for mid March, ahead of the July peak.
- Repellent can go away after November 21.
- 3 West Nile cases since 2016 (last 2023): you should use repellent at dusk June to September, more so if over 60.
Sumter County against the rest of SC
Sumter County has the 26th longest season of 46 SC counties, at 253 days against 349 in Charleston County and 209 in Cherokee County. Its mean temperature is 62.2°F.
- Marlboro County: March 12 to November 21 (254 days, 1 WNV)
- Abbeville County: March 13 to November 22 (254 days, 0 WNV)
- Allendale County: March 13 to November 19 (251 days, 1 WNV)
- Dillon County: March 14 to November 20 (251 days, 1 WNV)
West Nile in Sumter County
From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Sumter County (3 neuroinvasive) across 4 years. The worst was 2023 with 1; the latest was 2023.
See how the dates are worked out, and when mosquitoes go away for the winter.