Glen Ullin weather by month
What a typical year looks like in Glen Ullin, North Dakota: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Heart Butte Dam, 25 km from Glen Ullin; records cover 1984–2026.
The year at a glance
- Precipitation a year
- 16.8 in426 mm
- Snow a year
- 38 in96 cm
- Last spring freeze
- May 15
- First fall freeze
- Sep 30
- Heating degree days
- 8,599
- Cooling degree days
- 478
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −22°−30° (heating, 99%) and 97°36° (cooling, 1%).
Month by month
Glen Ullin in January
Highs average 25°−4° and lows 3°−16°, with 0.48 in12 mm of precipitation and 7 in19 cm of snow in a typical January.
- Record high
- 63°17° (2015)
- Record low
- −38°−39° (2009)
- Heating degree days
- 1588
- Cooling degree days
- 0
Glen Ullin in February
Highs average 29°−2° and lows 6°−14°, with 0.44 in11 mm of precipitation and 5 in13 cm of snow in a typical February.
- Record high
- 67°19° (1992)
- Record low
- −42°−41° (2025)
- Heating degree days
- 1326
- Cooling degree days
- 0
Glen Ullin in March
Highs average 41°5° and lows 17°−8°, with 0.71 in18 mm of precipitation and 5 in13 cm of snow in a typical March.
- Record high
- 84°29° (2012)
- Record low
- −31°−35° (1998)
- Heating degree days
- 1113
- Cooling degree days
- 0
Glen Ullin in April
Highs average 55°13° and lows 29°−2°, with 1.4 in35 mm of precipitation and 5 in12 cm of snow in a typical April.
- Record high
- 94°34° (1989)
- Record low
- −4°−20° (1997)
- Heating degree days
- 700
- Cooling degree days
- 0
Glen Ullin in May
Highs average 66°19° and lows 41°5°, with 2.2 in55 mm of precipitation and 0.6 in1.5 cm of snow in a typical May.
- Record high
- 95°35° (2025)
- Record low
- 17°−8° (2013)
- Heating degree days
- 358
- Cooling degree days
- 13
Glen Ullin in June
Highs average 76°25° and lows 52°11°, with 3.3 in83 mm of precipitation in a typical June.
- Record high
- 110°43° (2002)
- Record low
- 32°0° (2009)
- Heating degree days
- 99
- Cooling degree days
- 71
Glen Ullin in July
Highs average 84°29° and lows 57°14°, with 2.7 in68 mm of precipitation in a typical July.
- Record high
- 111°44° (2006)
- Record low
- 41°5° (2013)
- Heating degree days
- 24
- Cooling degree days
- 191
Glen Ullin in August
Highs average 83°28° and lows 55°13°, with 1.7 in44 mm of precipitation in a typical August.
- Record high
- 105°41° (2000)
- Record low
- 33°1° (1988)
- Heating degree days
- 42
- Cooling degree days
- 162
Glen Ullin in September
Highs average 73°23° and lows 45°7°, with 1.6 in41 mm of precipitation in a typical September.
- Record high
- 102°39° (2012)
- Record low
- 16°−9° (1991)
- Heating degree days
- 222
- Cooling degree days
- 39
Glen Ullin in OctoberThis month
Highs average 57°14° and lows 32°0°, with 1.3 in33 mm of precipitation and 2.5 in6.4 cm of snow in a typical October.
- Record high
- 97°36° (1989)
- Record low
- −3°−19° (1991)
- Heating degree days
- 648
- Cooling degree days
- 2
Glen Ullin in November
Highs average 41°5° and lows 19°−7°, with 0.58 in15 mm of precipitation and 6 in16 cm of snow in a typical November.
- Record high
- 83°28° (1999)
- Record low
- −28°−33° (1985)
- Heating degree days
- 1053
- Cooling degree days
- 0
Glen Ullin in December
Highs average 30°−1° and lows 9°−13°, with 0.44 in11 mm of precipitation and 6 in15 cm of snow in a typical December.
- Record high
- 67°19° (1998)
- Record low
- −37°−38° (1989)
- Heating degree days
- 1426
- Cooling degree days
- 0