Simms weather by month
What a typical year looks like in Simms, Montana: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Fairfield, 14 km from Simms; records cover 1927–2026.
The year at a glance
- Precipitation a year
- 12.4 in314 mm
- Snow a year
- Rare
- Last spring freeze
- May 11
- First fall freeze
- Sep 26
- Heating degree days
- 7,741
- Cooling degree days
- 255
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −16°−27° (heating, 99%) and 92°33° (cooling, 1%).
Month by month
Simms in January
Highs average 36°2° and lows 17°−9°, with 0.34 in8.6 mm of precipitation in a typical January.
- Record high
- 66°19° (2026)
- Record low
- −38°−39° (1929)
- Heating degree days
- 1206
- Cooling degree days
- 0
Simms in February
Highs average 36°2° and lows 17°−8°, with 0.43 in11 mm of precipitation in a typical February.
- Record high
- 74°23° (1992)
- Record low
- −44°−42° (1936)
- Heating degree days
- 1071
- Cooling degree days
- 0
Simms in March
Highs average 45°7° and lows 24°−5°, with 0.6 in15 mm of precipitation in a typical March.
- Record high
- 76°24° (1978)
- Record low
- −32°−36° (1951)
- Heating degree days
- 950
- Cooling degree days
- 0
Simms in April
Highs average 53°12° and lows 32°0°, with 1.4 in35 mm of precipitation in a typical April.
- Record high
- 85°29° (1939)
- Record low
- −12°−24° (1936)
- Heating degree days
- 686
- Cooling degree days
- 0
Simms in May
Highs average 62°17° and lows 41°5°, with 2.1 in54 mm of precipitation in a typical May.
- Record high
- 91°33° (1986)
- Record low
- 11°−12° (1954)
- Heating degree days
- 424
- Cooling degree days
- 5
Simms in June
Highs average 70°21° and lows 48°9°, with 2.6 in67 mm of precipitation in a typical June.
- Record high
- 97°36° (1941)
- Record low
- 28°−2° (2001)
- Heating degree days
- 213
- Cooling degree days
- 20
Simms in July
Highs average 80°27° and lows 53°12°, with 1.1 in27 mm of precipitation in a typical July.
- Record high
- 101°38° (1934)
- Record low
- 35°2° (1999)
- Heating degree days
- 63
- Cooling degree days
- 109
Simms in August
Highs average 79°26° and lows 52°11°, with 1.1 in27 mm of precipitation in a typical August.
- Record high
- 103°39° (1969)
- Record low
- 31°−1° (1992)
- Heating degree days
- 83
- Cooling degree days
- 97
Simms in September
Highs average 69°20° and lows 44°7°, with 1.2 in31 mm of precipitation in a typical September.
- Record high
- 97°36° (2022)
- Record low
- 13°−11° (2019)
- Heating degree days
- 285
- Cooling degree days
- 22
Simms in OctoberThis month
Highs average 55°13° and lows 34°1°, with 0.74 in19 mm of precipitation in a typical October.
- Record high
- 89°32° (1943)
- Record low
- −9°−23° (1935)
- Heating degree days
- 634
- Cooling degree days
- 2
Simms in November
Highs average 43°6° and lows 25°−4°, with 0.46 in12 mm of precipitation in a typical November.
- Record high
- 73°23° (1949)
- Record low
- −28°−33° (1959)
- Heating degree days
- 936
- Cooling degree days
- 0
Simms in December
Highs average 35°2° and lows 18°−8°, with 0.33 in8.4 mm of precipitation in a typical December.
- Record high
- 68°20° (2021)
- Record low
- −44°−42° (1968)
- Heating degree days
- 1190
- Cooling degree days
- 0