Mosquito season in Jefferson County, MS: when it starts and ends
Mosquito months in Jefferson County
In a normal year mosquito season in Jefferson County, MS starts around March 1 and ends around November 25, about 38 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Jefferson County, and when
- Start tipping out standing water weekly by February 15.
- Book any yard treatment for early March, ahead of the July peak.
- Repellent can go away after November 25.
- 1 West Nile case since 2016 (last 2019): you should use repellent at dusk May to September, more so if over 60.
Jefferson County against the rest of MS
Jefferson County has the 30th longest season of 82 MS counties, at 269 days against 333 in Harrison County and 221 in Tishomingo County. Its mean temperature is 65.2°F.
- Lincoln County: March 1 to November 28 (272 days, 8 WNV)
- Claiborne County: March 1 to November 25 (269 days, 2 WNV)
- Bolivar County: March 2 to November 26 (269 days, 2 WNV)
- Greene County: March 2 to November 26 (269 days, 0 WNV)
West Nile in Jefferson County
From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Jefferson County (2 neuroinvasive) across 2 years. The worst was 2019 with 1; the latest was 2019.
Background: when mosquitoes go away for the winter; how the dates are worked out.