Turtle Lake weather by month
What a typical year looks like in Turtle Lake, Montana: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Bigfork 13 S, 23 km from Turtle Lake; records cover 1938–2026.
The year at a glance
- Precipitation a year
- 21.4 in544 mm
- Snow a year
- Rare
- Last spring freeze
- May 2
- First fall freeze
- Oct 13
- Heating degree days
- 6,875
- Cooling degree days
- 250
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 5°−15° (heating, 99%) and 90°32° (cooling, 1%).
Month by month
Turtle Lake in January
Highs average 34°1° and lows 25°−4°, with 1.7 in44 mm of precipitation in a typical January.
- Record high
- 64°18° (1984)
- Record low
- −20°−29° (1950)
- Heating degree days
- 1099
- Cooling degree days
- 0
Turtle Lake in February
Highs average 37°3° and lows 26°−4°, with 1 in26 mm of precipitation in a typical February.
- Record high
- 62°17° (1962)
- Record low
- −21°−29° (1989)
- Heating degree days
- 946
- Cooling degree days
- 0
Turtle Lake in March
Highs average 45°7° and lows 30°−1°, with 1.3 in34 mm of precipitation in a typical March.
- Record high
- 69°21° (1939)
- Record low
- −11°−24° (1960)
- Heating degree days
- 854
- Cooling degree days
- 0
Turtle Lake in April
Highs average 53°12° and lows 35°2°, with 1.8 in45 mm of precipitation in a typical April.
- Record high
- 85°29° (1939)
- Record low
- 11°−12° (1951)
- Heating degree days
- 624
- Cooling degree days
- 0
Turtle Lake in May
Highs average 63°17° and lows 43°6°, with 2.5 in64 mm of precipitation in a typical May.
- Record high
- 90°32° (1966)
- Record low
- 21°−6° (1954)
- Heating degree days
- 372
- Cooling degree days
- 2
Turtle Lake in June
Highs average 70°21° and lows 49°10°, with 3.2 in81 mm of precipitation in a typical June.
- Record high
- 96°36° (2021)
- Record low
- 31°−1° (1980)
- Heating degree days
- 182
- Cooling degree days
- 19
Turtle Lake in July
Highs average 80°27° and lows 55°13°, with 1.3 in34 mm of precipitation in a typical July.
- Record high
- 100°38° (1940)
- Record low
- 30°−1° (1999)
- Heating degree days
- 40
- Cooling degree days
- 119
Turtle Lake in August
Highs average 79°26° and lows 54°12°, with 1.1 in28 mm of precipitation in a typical August.
- Record high
- 101°38° (1961)
- Record low
- 35°2° (1978)
- Heating degree days
- 44
- Cooling degree days
- 100
Turtle Lake in September
Highs average 69°21° and lows 47°8°, with 1.7 in44 mm of precipitation in a typical September.
- Record high
- 95°35° (1967)
- Record low
- 22°−6° (1965)
- Heating degree days
- 217
- Cooling degree days
- 10
Turtle Lake in OctoberThis month
Highs average 55°13° and lows 38°3°, with 2.4 in61 mm of precipitation in a typical October.
- Record high
- 82°28° (1942)
- Record low
- 8°−13° (1971)
- Heating degree days
- 570
- Cooling degree days
- 0
Turtle Lake in November
Highs average 42°5° and lows 32°0°, with 1.7 in44 mm of precipitation in a typical November.
- Record high
- 68°20° (1999)
- Record low
- −8°−22° (1959)
- Heating degree days
- 844
- Cooling degree days
- 0
Turtle Lake in December
Highs average 34°1° and lows 26°−3°, with 1.6 in40 mm of precipitation in a typical December.
- Record high
- 61°16° (1957)
- Record low
- −27°−33° (1978)
- Heating degree days
- 1083
- Cooling degree days
- 0