Cyr weather by month
What a typical year looks like in Cyr, Montana: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Alberton, 8 km from Cyr; records cover 1958–2026.
The year at a glance
- Precipitation a year
- 18.7 in474 mm
- Snow a year
- 49 in125 cm
- Last spring freeze
- May 22
- First fall freeze
- Sep 22
- Heating degree days
- 7,414
- Cooling degree days
- 282
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 99°37° (cooling, 1%).
Month by month
Cyr in January
Highs average 35°1° and lows 18°−8°, with 1.5 in37 mm of precipitation and 10 in26 cm of snow in a typical January.
- Record high
- 59°15° (2015)
- Record low
- −28°−33° (1963)
- Heating degree days
- 1200
- Cooling degree days
- 0
Cyr in February
Highs average 40°5° and lows 20°−7°, with 1.5 in38 mm of precipitation and 11 in28 cm of snow in a typical February.
- Record high
- 62°17° (2015)
- Record low
- −22°−30° (2014)
- Heating degree days
- 976
- Cooling degree days
- 0
Cyr in March
Highs average 49°9° and lows 25°−4°, with 1.7 in43 mm of precipitation and 6 in15 cm of snow in a typical March.
- Record high
- 80°27° (2004)
- Record low
- −12°−24° (2019)
- Heating degree days
- 877
- Cooling degree days
- 0
Cyr in April
Highs average 58°15° and lows 30°−1°, with 1.7 in42 mm of precipitation and 1.4 in3.6 cm of snow in a typical April.
- Record high
- 87°31° (2012)
- Record low
- 12°−11° (1966)
- Heating degree days
- 622
- Cooling degree days
- 0
Cyr in May
Highs average 68°20° and lows 38°3°, with 2 in52 mm of precipitation and 0.1 in0.3 cm of snow in a typical May.
- Record high
- 94°34° (2025)
- Record low
- 21°−6° (1972)
- Heating degree days
- 384
- Cooling degree days
- 3
Cyr in June
Highs average 75°24° and lows 44°7°, with 2.2 in56 mm of precipitation in a typical June.
- Record high
- 105°41° (2015)
- Record low
- 29°−2° (1969)
- Heating degree days
- 186
- Cooling degree days
- 28
Cyr in July
Highs average 87°30° and lows 49°9°, with 0.88 in22 mm of precipitation in a typical July.
- Record high
- 105°41° (2002)
- Record low
- 31°−1° (1971)
- Heating degree days
- 44
- Cooling degree days
- 129
Cyr in August
Highs average 87°30° and lows 47°8°, with 0.91 in23 mm of precipitation in a typical August.
- Record high
- 105°41° (1961)
- Record low
- 32°0° (1966)
- Heating degree days
- 50
- Cooling degree days
- 107
Cyr in September
Highs average 76°24° and lows 40°4°, with 1.1 in27 mm of precipitation and 0.1 in0.3 cm of snow in a typical September.
- Record high
- 100°38° (2022)
- Record low
- 21°−6° (1965)
- Heating degree days
- 236
- Cooling degree days
- 15
Cyr in OctoberThis month
Highs average 58°14° and lows 30°−1°, with 1.6 in42 mm of precipitation and 1.2 in3 cm of snow in a typical October.
- Record high
- 87°31° (2001)
- Record low
- −9°−23° (2019)
- Heating degree days
- 648
- Cooling degree days
- 0
Cyr in November
Highs average 41°5° and lows 24°−4°, with 2 in51 mm of precipitation and 6 in16 cm of snow in a typical November.
- Record high
- 71°22° (1999)
- Record low
- −12°−24° (1959)
- Heating degree days
- 974
- Cooling degree days
- 0
Cyr in December
Highs average 33°0° and lows 19°−7°, with 1.6 in41 mm of precipitation and 13 in33 cm of snow in a typical December.
- Record high
- 68°20° (2021)
- Record low
- −29°−34° (1964)
- Heating degree days
- 1217
- Cooling degree days
- 0