Flat Willow Colony weather by month
What a typical year looks like in Flat Willow Colony, Montana: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Flatwillow 4 Ene, 14 km from Flat Willow Colony; records cover 1913–2026.
The year at a glance
- Precipitation a year
- 14.2 in360 mm
- Snow a year
- 43 in110 cm
- Last spring freeze
- May 20
- First fall freeze
- Sep 22
- Heating degree days
- 7,169
- Cooling degree days
- 459
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −16°−27° (heating, 99%) and 99°37° (cooling, 1%).
Month by month
Flat Willow Colony in January
Highs average 36°2° and lows 14°−10°, with 0.48 in12 mm of precipitation and 10 in26 cm of snow in a typical January.
- Record high
- 72°22° (2005)
- Record low
- −42°−41° (1997)
- Heating degree days
- 1242
- Cooling degree days
- 0
Flat Willow Colony in February
Highs average 38°3° and lows 16°−9°, with 0.45 in11 mm of precipitation and 9 in23 cm of snow in a typical February.
- Record high
- 76°24° (1932)
- Record low
- −46°−43° (1936)
- Heating degree days
- 1060
- Cooling degree days
- 0
Flat Willow Colony in March
Highs average 48°9° and lows 24°−4°, with 0.58 in15 mm of precipitation and 5 in12 cm of snow in a typical March.
- Record high
- 80°27° (1978)
- Record low
- −30°−34° (1960)
- Heating degree days
- 888
- Cooling degree days
- 0
Flat Willow Colony in April
Highs average 58°14° and lows 32°0°, with 1.4 in36 mm of precipitation and 4 in11 cm of snow in a typical April.
- Record high
- 91°33° (1952)
- Record low
- −14°−26° (1940)
- Heating degree days
- 606
- Cooling degree days
- 0
Flat Willow Colony in May
Highs average 67°19° and lows 41°5°, with 2.8 in72 mm of precipitation and 0.2 in0.5 cm of snow in a typical May.
- Record high
- 98°37° (1934)
- Record low
- 8°−13° (1954)
- Heating degree days
- 350
- Cooling degree days
- 6
Flat Willow Colony in June
Highs average 76°24° and lows 50°10°, with 2.7 in69 mm of precipitation in a typical June.
- Record high
- 107°42° (1936)
- Record low
- 27°−3° (2009)
- Heating degree days
- 118
- Cooling degree days
- 47
Flat Willow Colony in July
Highs average 86°30° and lows 55°13°, with 1.3 in32 mm of precipitation in a typical July.
- Record high
- 111°44° (2026)
- Record low
- 34°1° (1918)
- Heating degree days
- 22
- Cooling degree days
- 191
Flat Willow Colony in August
Highs average 86°30° and lows 54°12°, with 1.1 in29 mm of precipitation in a typical August.
- Record high
- 108°42° (1949)
- Record low
- 30°−1° (1992)
- Heating degree days
- 32
- Cooling degree days
- 175
Flat Willow Colony in September
Highs average 75°24° and lows 45°7°, with 1.2 in30 mm of precipitation in a typical September.
- Record high
- 104°40° (1950)
- Record low
- 8°−13° (1926)
- Heating degree days
- 196
- Cooling degree days
- 38
Flat Willow Colony in OctoberThis month
Highs average 60°15° and lows 35°2°, with 1.2 in29 mm of precipitation and 2.3 in5.8 cm of snow in a typical October.
- Record high
- 94°34° (2011)
- Record low
- −18°−28° (1925)
- Heating degree days
- 554
- Cooling degree days
- 2
Flat Willow Colony in November
Highs average 46°8° and lows 24°−5°, with 0.5 in13 mm of precipitation and 4 in10 cm of snow in a typical November.
- Record high
- 81°27° (1917)
- Record low
- −29°−34° (1921)
- Heating degree days
- 900
- Cooling degree days
- 0
Flat Willow Colony in December
Highs average 37°3° and lows 16°−9°, with 0.48 in12 mm of precipitation and 9 in22 cm of snow in a typical December.
- Record high
- 70°21° (1956)
- Record low
- −48°−44° (1924)
- Heating degree days
- 1201
- Cooling degree days
- 0