Mosquito season in Jackson County, SD: when it starts and ends
Mosquito months in Jackson County
In a normal year mosquito season in Jackson County, SD starts around May 1 and ends around October 11, about 23 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Jackson County, and when
- Start tipping out standing water weekly by April 17.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 11.
- 1 West Nile case since 2016 (last 2017): you should use repellent at dusk July to August, more so if over 60.
Jackson County against the rest of SD
Jackson County has the 28th longest season of 66 SD counties, at 163 days against 179 in Yankton County and 139 in Lawrence County. Its mean temperature is 49°F.
- Ziebach County: April 29 to October 9 (163 days, 2 WNV)
- Mellette County: April 30 to October 10 (163 days, 4 WNV)
- Todd County: May 1 to October 11 (163 days, 3 WNV)
- McCook County: April 29 to October 8 (162 days, 9 WNV)
West Nile in Jackson County
From 1999 to 2025, CDC ArboNET counted 13 human West Nile cases in Jackson County (5 neuroinvasive) across 8 years. The worst was 2003 with 6; the latest was 2017.
See how the dates are worked out, and when mosquitoes go away for the winter.