Fort Belknap Agency weather by month
What a typical year looks like in Fort Belknap Agency, Montana: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Harlem 20s, 21 km from Fort Belknap Agency; records cover 2001–2026.
The year at a glance
- Precipitation a year
- 14.3 in362 mm
- Snow a year
- Rare
- Last spring freeze
- May 29
- First fall freeze
- Sep 18
- Heating degree days
- 8,073
- Cooling degree days
- 394
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −23°−31° (heating, 99%) and 99°37° (cooling, 1%).
Month by month
Fort Belknap Agency in January
Highs average 32°0° and lows 8°−13°, with 0.55 in14 mm of precipitation in a typical January.
- Record high
- 71°22° (2005)
- Record low
- −43°−42° (2024)
- Heating degree days
- 1390
- Cooling degree days
- 0
Fort Belknap Agency in February
Highs average 34°1° and lows 10°−12°, with 0.38 in9.7 mm of precipitation in a typical February.
- Record high
- 70°21° (2017)
- Record low
- −36°−38° (2019)
- Heating degree days
- 1201
- Cooling degree days
- 0
Fort Belknap Agency in March
Highs average 45°7° and lows 20°−7°, with 0.72 in18 mm of precipitation in a typical March.
- Record high
- 81°27° (2004)
- Record low
- −26°−32° (2003)
- Heating degree days
- 1015
- Cooling degree days
- 0
Fort Belknap Agency in April
Highs average 56°13° and lows 30°−1°, with 1.2 in31 mm of precipitation in a typical April.
- Record high
- 88°31° (2012)
- Record low
- −5°−21° (2020)
- Heating degree days
- 652
- Cooling degree days
- 1
Fort Belknap Agency in May
Highs average 66°19° and lows 39°4°, with 2.6 in65 mm of precipitation in a typical May.
- Record high
- 95°35° (2026)
- Record low
- 10°−12° (2009)
- Heating degree days
- 398
- Cooling degree days
- 9
Fort Belknap Agency in June
Highs average 75°24° and lows 48°9°, with 2.8 in70 mm of precipitation in a typical June.
- Record high
- 104°40° (2021)
- Record low
- 18°−8° (2009)
- Heating degree days
- 153
- Cooling degree days
- 43
Fort Belknap Agency in July
Highs average 86°30° and lows 52°11°, with 1.6 in42 mm of precipitation in a typical July.
- Record high
- 107°42° (2003)
- Record low
- 25°−4° (2008)
- Heating degree days
- 38
- Cooling degree days
- 158
Fort Belknap Agency in August
Highs average 85°30° and lows 51°10°, with 1.1 in28 mm of precipitation in a typical August.
- Record high
- 109°43° (2001)
- Record low
- 20°−7° (2008)
- Heating degree days
- 57
- Cooling degree days
- 148
Fort Belknap Agency in September
Highs average 74°23° and lows 42°5°, with 1.3 in34 mm of precipitation in a typical September.
- Record high
- 104°40° (2022)
- Record low
- 19°−7° (2007)
- Heating degree days
- 245
- Cooling degree days
- 32
Fort Belknap Agency in OctoberThis month
Highs average 59°15° and lows 30°−1°, with 0.98 in25 mm of precipitation in a typical October.
- Record high
- 92°33° (2011)
- Record low
- −5°−21° (2002)
- Heating degree days
- 635
- Cooling degree days
- 3
Fort Belknap Agency in November
Highs average 44°7° and lows 20°−7°, with 0.57 in14 mm of precipitation in a typical November.
- Record high
- 76°24° (2020)
- Record low
- −19°−28° (2006)
- Heating degree days
- 992
- Cooling degree days
- 0
Fort Belknap Agency in December
Highs average 35°2° and lows 11°−11°, with 0.39 in9.9 mm of precipitation in a typical December.
- Record high
- 69°21° (2021)
- Record low
- −39° (2013)
- Heating degree days
- 1297
- Cooling degree days
- 0