Mosquito season in McCone County, MT: when it starts and ends
Mosquito months in McCone County
In a normal year mosquito season in McCone County, MT 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 McCone 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.
- 7 West Nile cases since 2016 (last 2023): you should use repellent at dusk July to August, more so if over 60.
McCone County against the rest of MT
McCone County has the 16th longest season of 56 MT counties, at 148 days against 163 in Dawson County and 89 in Gallatin County. Its mean temperature is 44.4°F.
- Golden Valley County: May 7 to October 3 (149 days, 0 WNV)
- Carter County: May 6 to October 1 (148 days, 0 WNV)
- Blaine County: May 6 to September 30 (147 days, 4 WNV)
- Broadwater County: May 7 to October 1 (147 days, 1 WNV)
West Nile in McCone County
From 1999 to 2025, CDC ArboNET counted 14 human West Nile cases in McCone County (2 neuroinvasive) across 7 years. The worst was 2007 with 5; the latest was 2023.
More: how the dates are worked out · reading the West Nile counts.