Mosquito season in Foster County, ND: when it starts and ends
Mosquito months in Foster County
In a normal year mosquito season in Foster County, ND starts around May 6 and ends around October 1, about 21 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Foster 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 1.
- 3 West Nile cases since 2016 (last 2018): you should use repellent at dusk July, more so if over 60.
Foster County against the rest of ND
Foster County has the 30th longest season of 53 ND counties, at 148 days against 160 in Sheridan County and 135 in Rolette County. Its mean temperature is 40.3°F.
- Hettinger County: May 7 to October 3 (149 days, 5 WNV)
- Bottineau County: May 5 to September 30 (148 days, 6 WNV)
- McIntosh County: May 7 to October 2 (148 days, 4 WNV)
- Griggs County: May 7 to October 1 (147 days, 6 WNV)
West Nile in Foster County
From 1999 to 2025, CDC ArboNET counted 14 human West Nile cases in Foster County (4 neuroinvasive) across 7 years. The worst was 2003 with 6; the latest was 2018.
See how the dates are worked out, and when the season starts across the US.