Iron Mountain weather by month
What a typical year looks like in Iron Mountain, Michigan: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Iron Mtn-Kingsford Wwtp, 5 km from Iron Mountain; records cover 1899–2026.
The year at a glance
- Precipitation a year
- 31.5 in800 mm
- Snow a year
- 61 in155 cm
- Last spring freeze
- May 20
- First fall freeze
- Sep 29
- Heating degree days
- 8,523
- Cooling degree days
- 371
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −18°−28° (heating, 99%) and 91°33° (cooling, 1%).
Month by month
Iron Mountain in January
Highs average 24°−4° and lows 4°−15°, with 1.4 in35 mm of precipitation and 15 in37 cm of snow in a typical January.
- Record high
- 57°14° (1911)
- Record low
- −35°−37° (1948)
- Heating degree days
- 1575
- Cooling degree days
- 0
Iron Mountain in February
Highs average 28°−2° and lows 6°−14°, with 1.2 in29 mm of precipitation and 11 in28 cm of snow in a typical February.
- Record high
- 65°18° (2024)
- Record low
- −39° (1938)
- Heating degree days
- 1338
- Cooling degree days
- 0
Iron Mountain in March
Highs average 39°4° and lows 17°−8°, with 1.7 in43 mm of precipitation and 9 in23 cm of snow in a typical March.
- Record high
- 82°28° (2012)
- Record low
- −27°−33° (1939)
- Heating degree days
- 1146
- Cooling degree days
- 0
Iron Mountain in April
Highs average 52°11° and lows 29°−2°, with 2.8 in71 mm of precipitation and 7 in18 cm of snow in a typical April.
- Record high
- 94°34° (1980)
- Record low
- −6°−21° (1972)
- Heating degree days
- 737
- Cooling degree days
- 0
Iron Mountain in May
Highs average 66°19° and lows 42°5°, with 3.5 in88 mm of precipitation and 0.2 in0.5 cm of snow in a typical May.
- Record high
- 100°38° (1934)
- Record low
- 16°−9° (1990)
- Heating degree days
- 357
- Cooling degree days
- 18
Iron Mountain in June
Highs average 76°24° and lows 52°11°, with 3.7 in94 mm of precipitation in a typical June.
- Record high
- 100°38° (1911)
- Record low
- 24°−4° (1949)
- Heating degree days
- 103
- Cooling degree days
- 73
Iron Mountain in July
Highs average 80°27° and lows 57°14°, with 3.4 in87 mm of precipitation in a typical July.
- Record high
- 104°40° (1917)
- Record low
- 35°2° (1939)
- Heating degree days
- 36
- Cooling degree days
- 144
Iron Mountain in August
Highs average 78°26° and lows 55°13°, with 3.4 in86 mm of precipitation in a typical August.
- Record high
- 101°38° (1947)
- Record low
- 30°−1° (1945)
- Heating degree days
- 52
- Cooling degree days
- 104
Iron Mountain in September
Highs average 70°21° and lows 47°8°, with 3.6 in91 mm of precipitation in a typical September.
- Record high
- 98°37° (1998)
- Record low
- 19°−7° (1942)
- Heating degree days
- 225
- Cooling degree days
- 31
Iron Mountain in OctoberThis month
Highs average 56°13° and lows 35°2°, with 3.3 in83 mm of precipitation and 0.4 in1 cm of snow in a typical October.
- Record high
- 88°31° (1947)
- Record low
- 8°−13° (1925)
- Heating degree days
- 612
- Cooling degree days
- 1
Iron Mountain in November
Highs average 41°5° and lows 24°−4°, with 1.9 in48 mm of precipitation and 6 in14 cm of snow in a typical November.
- Record high
- 77°25° (2020)
- Record low
- −10°−23° (1976)
- Heating degree days
- 975
- Cooling degree days
- 0
Iron Mountain in December
Highs average 29°−2° and lows 13°−11°, with 1.8 in45 mm of precipitation and 13 in33 cm of snow in a typical December.
- Record high
- 64°18° (1998)
- Record low
- −26°−32° (1976)
- Heating degree days
- 1367
- Cooling degree days
- 0