Mosquito season in Renville County, ND: when it starts and ends
Mosquito months in Renville County
In a normal year mosquito season in Renville County, ND starts around May 9 and ends around September 28, about 20 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Renville County, and when
- Start tipping out standing water weekly by April 25.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after September 28.
- No West Nile cases since 2016, so bites in Renville County are a nuisance; check window screens.
Renville County against the rest of ND
Renville County has the 44th longest season of 53 ND counties, at 142 days against 160 in Sheridan County and 135 in Rolette County. Its mean temperature is 39.1°F.
- Dunn County: May 9 to September 30 (144 days, 3 WNV)
- Grant County: May 11 to October 2 (144 days, 1 WNV)
- Divide County: May 9 to September 27 (141 days, 2 WNV)
- Mercer County: May 11 to September 28 (140 days, 25 WNV)
West Nile in Renville County
From 1999 to 2025, CDC ArboNET counted 8 human West Nile cases in Renville County (0 neuroinvasive) across 2 years. The worst was 2003 with 7; the latest was 2007.
Background: when the season starts across the US; how the dates are worked out.