Mosquito season in Wells County, ND: when it starts and ends
Mosquito months in Wells County
In a normal year mosquito season in Wells County, ND starts around May 5 and ends around October 3, about 21 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Wells County, and when
- Start tipping out standing water weekly by April 21.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 3.
- 5 West Nile cases since 2016 (last 2018): you should use repellent at dusk July, more so if over 60.
Wells County against the rest of ND
Wells County has the 18th longest season of 53 ND counties, at 150 days against 160 in Sheridan County and 135 in Rolette County. Its mean temperature is 40.8°F.
- McHenry County: May 4 to October 2 (151 days, 14 WNV)
- Ward County: May 4 to October 2 (151 days, 35 WNV)
- Billings County: May 6 to October 3 (150 days, 1 WNV)
- Golden Valley County: May 6 to October 3 (150 days, 2 WNV)
West Nile in Wells County
From 1999 to 2025, CDC ArboNET counted 20 human West Nile cases in Wells County (4 neuroinvasive) across 9 years. The worst was 2003 with 5; the latest was 2018.
More: how the dates are worked out · reading the West Nile counts.