Rockvale weather by month
What a typical year looks like in Rockvale, Montana: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Bridger 2 N, 22 km from Rockvale; records cover 1900–2026.
The year at a glance
- Precipitation a year
- 11.5 in292 mm
- Snow a year
- 30 in77 cm
- Last spring freeze
- May 13
- First fall freeze
- Sep 22
- Heating degree days
- 7,414
- Cooling degree days
- 414
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −11°−24° (heating, 99%) and 100°38° (cooling, 1%).
Month by month
Rockvale in January
Highs average 35°2° and lows 13°−11°, with 0.29 in7.4 mm of precipitation and 5 in13 cm of snow in a typical January.
- Record high
- 73°23° (1919)
- Record low
- −34°−37° (1930)
- Heating degree days
- 1266
- Cooling degree days
- 0
Rockvale in February
Highs average 39°4° and lows 15°−9°, with 0.33 in8.4 mm of precipitation and 5 in11 cm of snow in a typical February.
- Record high
- 71°22° (1951)
- Record low
- −35°−37° (1936)
- Heating degree days
- 1064
- Cooling degree days
- 0
Rockvale in March
Highs average 50°10° and lows 22°−5°, with 0.47 in12 mm of precipitation and 3 in8 cm of snow in a typical March.
- Record high
- 85°29° (2026)
- Record low
- −26°−32° (1920)
- Heating degree days
- 887
- Cooling degree days
- 0
Rockvale in April
Highs average 58°14° and lows 30°−1°, with 1.6 in40 mm of precipitation and 4 in9 cm of snow in a typical April.
- Record high
- 89°32° (2012)
- Record low
- −4°−20° (2018)
- Heating degree days
- 636
- Cooling degree days
- 0
Rockvale in May
Highs average 67°20° and lows 40°4°, with 2.3 in57 mm of precipitation and 0.7 in1.8 cm of snow in a typical May.
- Record high
- 98°37° (1919)
- Record low
- 16°−9° (1931)
- Heating degree days
- 365
- Cooling degree days
- 8
Rockvale in June
Highs average 77°25° and lows 47°8°, with 1.8 in46 mm of precipitation in a typical June.
- Record high
- 106°41° (1919)
- Record low
- 27°−3° (1916)
- Heating degree days
- 132
- Cooling degree days
- 47
Rockvale in July
Highs average 87°31° and lows 53°12°, with 0.83 in21 mm of precipitation in a typical July.
- Record high
- 112°44° (2026)
- Record low
- 35°2° (1915)
- Heating degree days
- 23
- Cooling degree days
- 182
Rockvale in August
Highs average 86°30° and lows 50°10°, with 0.61 in15 mm of precipitation in a typical August.
- Record high
- 107°42° (2026)
- Record low
- 28°−2° (1992)
- Heating degree days
- 45
- Cooling degree days
- 145
Rockvale in September
Highs average 75°24° and lows 42°5°, with 1.2 in29 mm of precipitation in a typical September.
- Record high
- 105°41° (2020)
- Record low
- 9°−13° (1926)
- Heating degree days
- 228
- Cooling degree days
- 30
Rockvale in OctoberThis month
Highs average 60°15° and lows 32°0°, with 1.2 in31 mm of precipitation and 2 in5.1 cm of snow in a typical October.
- Record high
- 92°33° (2011)
- Record low
- −13°−25° (1919)
- Heating degree days
- 600
- Cooling degree days
- 2
Rockvale in November
Highs average 46°8° and lows 22°−5°, with 0.6 in15 mm of precipitation and 5 in12 cm of snow in a typical November.
- Record high
- 78°26° (1999)
- Record low
- −26°−32° (1959)
- Heating degree days
- 930
- Cooling degree days
- 0
Rockvale in December
Highs average 36°2° and lows 14°−10°, with 0.37 in9.4 mm of precipitation and 7 in17 cm of snow in a typical December.
- Record high
- 72°22° (1980)
- Record low
- −37°−38° (1983)
- Heating degree days
- 1238
- Cooling degree days
- 0