Mosquito season in Jerauld County, SD: when it starts and ends

Mosquito months in Jerauld County

In a normal year mosquito season in Jerauld County, SD starts around April 29 and ends around October 10, about 24 weeks.

1. Jan
2. Feb
3. Mar
4. Apr
5. May
6. Jun
7. Jul
8. Aug
9. Sep
10. Oct
11. Nov
12. Dec

What to do in Jerauld County, and when

• Start tipping out standing water weekly by April 15.
• Book any yard treatment for late April, ahead of the July peak.
• Repellent can go away after October 10.
• 5 West Nile cases since 2016 (last 2023): you should use repellent at dusk July to August, more so if over 60.

Jerauld County against the rest of SD

Jerauld County has the 20th longest season of 66 SD counties, at 165 days against 179 in Yankton County and 139 in Lawrence County. Its mean temperature is 45.4°F.

• Lake County: April 27 to October 10 (166 days, 11 WNV)
• Haakon County: April 29 to October 11 (165 days, 1 WNV)
• Sully County: April 29 to October 11 (165 days, 3 WNV)
• Oglala Lakota County: April 30 to October 12 (165 days, 9 WNV)

West Nile in Jerauld County

From 1999 to 2025, CDC ArboNET counted 12 human West Nile cases in Jerauld County (4 neuroinvasive) across 8 years. The worst was 2016 with 2; the latest was 2023.

See how the dates are worked out, and reading the West Nile counts.