Mosquito season in Chester County, SC: when it starts and ends
Mosquito months in Chester County
In a normal year mosquito season in Chester County, SC starts around March 20 and ends around November 13, about 34 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Chester County, and when
- Start tipping out standing water weekly by March 6.
- Book any yard treatment for mid March, ahead of the July peak.
- Repellent can go away after November 13.
- 1 West Nile case since 2016 (last 2021): you should use repellent at dusk June to September, more so if over 60.
Chester County against the rest of SC
Chester County has the 40th longest season of 46 SC counties, at 238 days against 349 in Charleston County and 209 in Cherokee County. Its mean temperature is 60.4°F.
- Lexington County: March 17 to November 14 (242 days, 6 WNV)
- Pickens County: March 20 to November 15 (240 days, 1 WNV)
- York County: March 21 to November 14 (238 days, 6 WNV)
- Chesterfield County: March 21 to November 13 (237 days, 0 WNV)
West Nile in Chester County
From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Chester County (1 neuroinvasive) across 2 years. The worst was 2021 with 1; the latest was 2021.
Background: when mosquitoes go away for the winter; how the dates are worked out.