Charlo weather by month
What a typical year looks like in Charlo, Montana: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Saint Ignatius, 15 km from Charlo; records cover 1896–2026.
The year at a glance
- Precipitation a year
- 16.7 in425 mm
- Snow a year
- Rare
- Last spring freeze
- May 16
- First fall freeze
- Sep 24
- Heating degree days
- 6,654
- Cooling degree days
- 360
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −4°−20° (heating, 99%) and 95°35° (cooling, 1%).
Month by month
Charlo in January
Highs average 37°3° and lows 23°−5°, with 0.95 in24 mm of precipitation in a typical January.
- Record high
- 67°19° (1992)
- Record low
- −34°−37° (1937)
- Heating degree days
- 1094
- Cooling degree days
- 0
Charlo in February
Highs average 40°4° and lows 22°−5°, with 1.2 in29 mm of precipitation in a typical February.
- Record high
- 68°20° (1995)
- Record low
- −36°−38° (1936)
- Heating degree days
- 949
- Cooling degree days
- 0
Charlo in March
Highs average 51°10° and lows 28°−2°, with 0.94 in24 mm of precipitation in a typical March.
- Record high
- 82°28° (1986)
- Record low
- −17°−27° (1932)
- Heating degree days
- 797
- Cooling degree days
- 0
Charlo in April
Highs average 59°15° and lows 34°1°, with 1.8 in44 mm of precipitation in a typical April.
- Record high
- 89°32° (1910)
- Record low
- −5°−21° (1936)
- Heating degree days
- 550
- Cooling degree days
- 0
Charlo in May
Highs average 69°20° and lows 41°5°, with 2.3 in58 mm of precipitation in a typical May.
- Record high
- 96°36° (1936)
- Record low
- 19°−7° (1954)
- Heating degree days
- 323
- Cooling degree days
- 7
Charlo in June
Highs average 75°24° and lows 47°8°, with 2.6 in67 mm of precipitation in a typical June.
- Record high
- 101°38° (1986)
- Record low
- 22°−6° (2008)
- Heating degree days
- 154
- Cooling degree days
- 31
Charlo in July
Highs average 86°30° and lows 52°11°, with 0.97 in25 mm of precipitation in a typical July.
- Record high
- 103°39° (1953)
- Record low
- 30°−1° (2010)
- Heating degree days
- 35
- Cooling degree days
- 162
Charlo in August
Highs average 86°30° and lows 51°10°, with 1.2 in30 mm of precipitation in a typical August.
- Record high
- 103°39° (1897)
- Record low
- 27°−3° (1910)
- Heating degree days
- 38
- Cooling degree days
- 138
Charlo in September
Highs average 75°24° and lows 44°7°, with 1.5 in38 mm of precipitation in a typical September.
- Record high
- 98°37° (1967)
- Record low
- 4°−16° (1926)
- Heating degree days
- 188
- Cooling degree days
- 22
Charlo in OctoberThis month
Highs average 59°15° and lows 35°1°, with 1.3 in33 mm of precipitation in a typical October.
- Record high
- 87°31° (1980)
- Record low
- −7°−22° (1935)
- Heating degree days
- 560
- Cooling degree days
- 0
Charlo in November
Highs average 45°7° and lows 28°−2°, with 1.1 in29 mm of precipitation in a typical November.
- Record high
- 73°23° (1908)
- Record low
- −27°−33° (1959)
- Heating degree days
- 866
- Cooling degree days
- 0
Charlo in December
Highs average 37°3° and lows 23°−5°, with 0.94 in24 mm of precipitation in a typical December.
- Record high
- 67°19° (1941)
- Record low
- −35°−37° (1927)
- Heating degree days
- 1100
- Cooling degree days
- 0