September weather in Forsyth, MT
The average temperature in Forsyth in September is 60.5°F (45.6°F–75.4°F). Average precipitation: 1.38 inches.
September is a fall month in Forsyth, and is warmer than the annual average of 46.7°F. Daily temperatures swing about 29.8°F between overnight low and afternoon high. Expect about 6 days with precipitation. Daylight averages about 12h 19m. For travel, September is a comfortable month to visit.
Avg High
75.4°F
Avg Low
45.6°F
Precipitation
1.38 in
Snow
0.1 in
September records in Forsyth
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 102.0°F (1983) | 39.9°F (2005) | 2.05 in (1986) |
| September 2 | 98.1°F (1998) | 39.9°F (2006) | 0.25 in (1999) |
| September 3 | 100.9°F (2022) | 39.9°F (2006) | 0.40 in (1999) |
| September 4 | 100.9°F (1998) | 36.0°F (2011) | 0.30 in (1999) |
| September 5 | 98.1°F (1976) | 37.0°F (2014) | 0.48 in (2016) |
| September 6 | 97.0°F (1980) | 35.1°F (1989) | 0.47 in (2001) |
| September 7 | 105.1°F (2022) | 36.0°F (1993) | 0.48 in (2020) |
| September 8 | 99.0°F (1998) | 33.1°F (2020) | 0.71 in (2002) |
| September 9 | 100.0°F (2005) | 30.0°F (1976) | 1.00 in (2013) |
| September 10 | 91.0°F (1997) | 30.0°F (1992) | 0.52 in (2008) |
| September 11 | 90.0°F (1981) | 23.0°F (1989) | 2.80 in (2019) |
| September 12 | 93.9°F (1990) | 23.0°F (1989) | 0.93 in (1978) |
| September 13 | 91.0°F (2015) | 30.0°F (1989) | 1.21 in (1978) |
| September 14 | 90.0°F (2012) | 28.0°F (1993) | 1.02 in (1982) |
| September 15 | 96.1°F (1998) | 32.0°F (2014) | 2.02 in (1991) |
| September 16 | 95.0°F (2000) | 33.1°F (1984) | 0.68 in (2022) |
| September 17 | 93.9°F (1979) | 32.0°F (1981) | 0.82 in (1996) |
| September 18 | 93.9°F (1984) | 26.1°F (1991) | 1.08 in (1978) |
| September 19 | 95.0°F (2009) | 28.9°F (1991) | 0.81 in (1983) |
| September 20 | 89.1°F (2008) | 30.0°F (1982) | 0.52 in (2018) |
| September 21 | 87.1°F (2025) | 21.9°F (1995) | 0.45 in (2019) |
| September 22 | 88.0°F (2007) | 24.1°F (1995) | 2.28 in (2023) |
| September 23 | 96.1°F (1992) | 27.0°F (1993) | 0.55 in (2007) |
| September 24 | 93.9°F (2020) | 26.1°F (2000) | 1.40 in (2016) |
| September 25 | 95.0°F (2015) | 23.0°F (1984) | 2.68 in (1986) |
| September 26 | 93.9°F (2015) | 28.9°F (1985) | 0.36 in (1999) |
| September 27 | 91.0°F (2001) | 26.1°F (1976) | 0.48 in (1982) |
| September 28 | 96.1°F (2001) | 28.0°F (1976) | 1.00 in (2019) |
| September 29 | 98.1°F (2024) | 21.0°F (1984) | 0.15 in (2019) |
| September 30 | 91.0°F (1997) | 19.0°F (1985) | 0.60 in (1977) |