Mosquito season in Grainger County, TN: when it starts and ends
Mosquito months in Grainger County
In a normal year mosquito season in Grainger County, TN starts around April 11 and ends around October 27, about 28 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Grainger County, and when
- Start tipping out standing water weekly by March 28.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 27.
- No West Nile cases since 2016, so bites in Grainger County are a nuisance; check window screens.
Grainger County against the rest of TN
Grainger County has the 93rd longest season of 95 TN counties, at 199 days against 252 in Hamilton County and 186 in Carter County. Its mean temperature is 56.9°F.
- Scott County: April 7 to October 27 (203 days, 0 WNV)
- Claiborne County: April 10 to October 28 (201 days, 0 WNV)
- Johnson County: April 12 to October 24 (195 days, 0 WNV)
- Carter County: April 20 to October 23 (186 days, 0 WNV)
West Nile in Grainger County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Grainger County (1 neuroinvasive) across 1 year. The worst was 2002 with 1; the latest was 2002.
More: how the dates are worked out · when the season starts across the US.