Three Sisters Group Site (MT)

Nights by month

Night lows from 2016 to 2025: a typical night, and the cold one that comes 1 night in 10.

The mildest nights are in July, typically 51°F. The coldest are in January, when 1 night in 10 drops to 1°F. Frost is common in January, February, March, April, May, October, November and December.

1. Jan17°F 1°FBag comfortable to 0°F · frost 99% · rain or snow 36% of days
2. Feb18°F 0°FBag comfortable to 0°F · frost 93% · rain or snow 53% of days
3. Mar24°F 10°FBag comfortable to 10°F · frost 90% · rain or snow 47% of days
4. Apr29°F 21°FBag comfortable to 20°F · frost 70% · rain or snow 46% of days
5. May37°F 28°FBag comfortable to 30°F · frost 23% · rain or snow 39% of days
6. Jun44°F 37°FBag comfortable to 35°F · frost 3% · rain or snow 32% of days
7. Jul51°F 44°FBag comfortable to 45°F · frost 0% · rain or snow 12% of days
8. Aug50°F 44°FBag comfortable to 45°F · frost 0% · rain or snow 17% of days
9. Sep43°F 35°FBag comfortable to 35°F · frost 5% · rain or snow 24% of days
10. Oct34°F 24°FBag comfortable to 25°F · frost 41% · rain or snow 38% of days
11. Nov (this month)26°F 13°FBag comfortable to 15°F · frost 80% · rain or snow 38% of days
12. Dec21°F 3°FBag comfortable to 5°F · frost 92% · rain or snow 45% of days

| = 32°F

History: ERA5 and ERA5-Land reanalysis via Open-Meteo, corrected to the site's elevation. Bag rating: the comfort rating that keeps you warm in a tent on 9 of 10 nights that month.