September weather in Iron Mountain, MI
The average temperature in Iron Mountain in September is 57.4°F (45.2°F–69.5°F). Average precipitation: 2.94 inches.
September is a fall month in Iron Mountain, and is warmer than the annual average of 41.8°F. Daily temperatures swing about 24.3°F between overnight low and afternoon high. Expect about 12 days with precipitation. Daylight averages about 12h 18m. For travel, September is a comfortable month to visit.
Avg High
69.5°F
Avg Low
45.2°F
Precipitation
2.94 in
Daylight
12h 18m
September records in Iron Mountain
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 89.1°F (2008) | 33.1°F (2001) | 0.93 in (2013) |
| September 2 | 91.0°F (2008) | 39.9°F (2016) | 1.18 in (2015) |
| September 3 | 89.1°F (1999) | 35.1°F (1997) | 1.16 in (2014) |
| September 4 | 93.0°F (2023) | 10.0°F (2005) | 1.83 in (2014) |
| September 5 | 91.0°F (1998) | 36.0°F (2003) | 1.32 in (2018) |
| September 6 | 87.1°F (2007) | 35.1°F (2011) | 0.62 in (2010) |
| September 7 | 90.0°F (2002) | 37.0°F (2011) | 0.87 in (2021) |
| September 8 | 88.0°F (2002) | 34.0°F (2017) | 0.33 in (2006) |
| September 9 | 91.0°F (2002) | 33.1°F (2017) | 0.38 in (2019) |
| September 10 | 86.0°F (2013) | 31.1°F (2006) | 1.42 in (2014) |
| September 11 | 97.0°F (1998) | 33.1°F (2020) | 0.61 in (2008) |
| September 12 | 89.1°F (2005) | 34.0°F (2014) | 1.16 in (2019) |
| September 13 | 87.1°F (2005) | 35.1°F (2014) | 0.52 in (2008) |
| September 14 | 86.0°F (2018) | 32.0°F (2001) | 0.63 in (2003) |
| September 15 | 88.0°F (2024) | 29.1°F (2007) | 1.19 in (2010) |
| September 16 | 89.1°F (2024) | 26.2°F (2011) | 1.15 in (2016) |
| September 17 | 87.1°F (2025) | 29.1°F (2011) | 0.34 in (2012) |
| September 18 | 88.0°F (1999) | 29.1°F (2020) | 0.24 in (2007) |
| September 19 | 86.0°F (1998) | 29.1°F (2012) | 0.47 in (2013) |
| September 20 | 82.0°F (2024) | 30.9°F (1999) | 0.54 in (2002) |
| September 21 | 84.0°F (2007) | 28.0°F (1999) | 1.21 in (2007) |
| September 22 | 84.0°F (2017) | 28.9°F (1998) | 0.58 in (2001) |
| September 23 | 90.0°F (2017) | 26.1°F (1998) | 3.31 in (2010) |
| September 24 | 89.1°F (2017) | 28.0°F (2000) | 0.61 in (2020) |
| September 25 | 88.0°F (2017) | 28.9°F (2000) | 0.65 in (2005) |
| September 26 | 82.0°F (2024) | 28.2°F (2012) | 0.66 in (1998) |
| September 27 | 84.0°F (2024) | 28.2°F (2012) | 0.53 in (2009) |
| September 28 | 84.0°F (2024) | 26.1°F (2000) | 0.98 in (2005) |
| September 29 | 82.9°F (2025) | 27.0°F (2004) | 0.30 in (2011) |
| September 30 | 79.0°F (2024) | 27.0°F (2003) | 0.71 in (2023) |