Mosquito season in Sullivan County, TN: when it starts and ends
Mosquito months in Sullivan County
In a normal year mosquito season in Sullivan County, TN starts around April 1 and ends around November 1, about 31 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Sullivan County, and when
- Start tipping out standing water weekly by March 18.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after November 1.
- 1 West Nile case since 2016 (last 2017): you should use repellent at dusk June to August, more so if over 60.
Sullivan County against the rest of TN
Sullivan County has the 70th longest season of 95 TN counties, at 214 days against 252 in Hamilton County and 186 in Carter County. Its mean temperature is 56.5°F.
- Wayne County: April 2 to November 3 (215 days, 0 WNV)
- Coffee County: April 1 to November 1 (214 days, 0 WNV)
- Fentress County: April 2 to November 2 (214 days, 0 WNV)
- Moore County: April 2 to November 2 (214 days, 0 WNV)
West Nile in Sullivan County
From 1999 to 2025, CDC ArboNET counted 7 human West Nile cases in Sullivan County (6 neuroinvasive) across 4 years. The worst was 2003 with 3; the latest was 2017.
See how the dates are worked out, and when mosquitoes go away for the winter.