Bynum weather by month
What a typical year looks like in Bynum, Montana: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Choteau, 19 km from Bynum; records cover 1893–2026.
The year at a glance
- Precipitation a year
- 11.9 in303 mm
- Snow a year
- 48 in121 cm
- Last spring freeze
- May 26
- First fall freeze
- Sep 10
- Heating degree days
- 7,847
- Cooling degree days
- 156
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −18°−28° (heating, 99%) and 92°33° (cooling, 1%).
Month by month
Bynum in January
Highs average 37°3° and lows 13°−10°, with 0.28 in7.1 mm of precipitation and 6 in16 cm of snow in a typical January.
- Record high
- 79°26° (1919)
- Record low
- −44°−42° (1943)
- Heating degree days
- 1228
- Cooling degree days
- 0
Bynum in February
Highs average 39°4° and lows 14°−10°, with 0.41 in10 mm of precipitation and 8 in19 cm of snow in a typical February.
- Record high
- 73°23° (2016)
- Record low
- −50°−46° (1936)
- Heating degree days
- 1077
- Cooling degree days
- 0
Bynum in March
Highs average 47°8° and lows 21°−6°, with 0.52 in13 mm of precipitation and 8 in21 cm of snow in a typical March.
- Record high
- 82°28° (1910)
- Record low
- −36°−38° (1932)
- Heating degree days
- 961
- Cooling degree days
- 0
Bynum in April
Highs average 56°13° and lows 29°−2°, with 1.2 in29 mm of precipitation and 7 in17 cm of snow in a typical April.
- Record high
- 86°30° (1987)
- Record low
- −16°−27° (1935)
- Heating degree days
- 680
- Cooling degree days
- 0
Bynum in May
Highs average 65°18° and lows 37°3°, with 2.1 in54 mm of precipitation and 1.4 in3.6 cm of snow in a typical May.
- Record high
- 92°33° (1919)
- Record low
- 8°−13° (1954)
- Heating degree days
- 434
- Cooling degree days
- 2
Bynum in June
Highs average 72°22° and lows 44°7°, with 2.8 in70 mm of precipitation in a typical June.
- Record high
- 98°37° (2021)
- Record low
- 28°−2° (1909)
- Heating degree days
- 217
- Cooling degree days
- 13
Bynum in July
Highs average 82°28° and lows 48°9°, with 0.99 in25 mm of precipitation in a typical July.
- Record high
- 105°41° (1893)
- Record low
- 28°−2° (1999)
- Heating degree days
- 67
- Cooling degree days
- 72
Bynum in August
Highs average 81°27° and lows 47°8°, with 1.1 in27 mm of precipitation in a typical August.
- Record high
- 106°41° (1894)
- Record low
- 28°−2° (2015)
- Heating degree days
- 90
- Cooling degree days
- 57
Bynum in September
Highs average 72°22° and lows 40°4°, with 1.2 in29 mm of precipitation and 0.9 in2.3 cm of snow in a typical September.
- Record high
- 96°36° (1893)
- Record low
- −5°−21° (1926)
- Heating degree days
- 289
- Cooling degree days
- 10
Bynum in OctoberThis month
Highs average 58°14° and lows 31°−1°, with 0.74 in19 mm of precipitation and 4 in11 cm of snow in a typical October.
- Record high
- 90°32° (1992)
- Record low
- −15°−26° (1919)
- Heating degree days
- 644
- Cooling degree days
- 2
Bynum in November
Highs average 45°7° and lows 22°−6°, with 0.41 in10 mm of precipitation and 7 in18 cm of snow in a typical November.
- Record high
- 80°27° (1962)
- Record low
- −30°−34° (1896)
- Heating degree days
- 951
- Cooling degree days
- 0
Bynum in December
Highs average 37°3° and lows 15°−10°, with 0.32 in8.1 mm of precipitation and 5 in14 cm of snow in a typical December.
- Record high
- 72°22° (1939)
- Record low
- −43°−42° (1968)
- Heating degree days
- 1209
- Cooling degree days
- 0