Mosquito season in Billings County, ND: when it starts and ends
Mosquito months in Billings County
In a normal year mosquito season in Billings County, ND starts around May 6 and ends around October 3, about 21 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Billings County, and when
- Start tipping out standing water weekly by April 22.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 3.
- 1 West Nile case since 2016 (last 2018): you should use repellent at dusk July to July, more so if over 60.
Billings County against the rest of ND
Billings County has the 19th longest season of 53 ND counties, at 150 days against 160 in Sheridan County and 135 in Rolette County. Its mean temperature is 43.1°F.
- Ward County: May 4 to October 2 (151 days, 35 WNV)
- Wells County: May 5 to October 3 (150 days, 5 WNV)
- Golden Valley County: May 6 to October 3 (150 days, 2 WNV)
- McLean County: May 6 to October 3 (150 days, 15 WNV)
West Nile in Billings County
From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Billings County (2 neuroinvasive) across 2 years. The worst was 2018 with 1; the latest was 2018.
Background: when mosquitoes go away for the winter; how the dates are worked out.