September weather in Circle, MT
The average temperature in Circle in September is 60.3°F (45.2°F–75.5°F). Average precipitation: 1.33 inches.
September is a fall month in Circle, and is warmer than the annual average of 45.1°F. Daily temperatures swing about 30.3°F between overnight low and afternoon high. Expect about 5 days with precipitation. Daylight averages about 12h 19m. For travel, September is a comfortable month to visit.
Avg High
75.5°F
Avg Low
45.2°F
Precipitation
1.33 in
Daylight
12h 19m
September records in Circle
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 102.0°F (1983) | 33.1°F (1974) | 0.40 in (1971) |
| September 2 | 105.1°F (1983) | 27.0°F (1974) | 0.70 in (1999) |
| September 3 | 100.0°F (2005) | 28.9°F (1974) | 1.88 in (1973) |
| September 4 | 102.0°F (1998) | 33.1°F (1974) | 0.46 in (1973) |
| September 5 | 100.0°F (1978) | 25.0°F (1965) | 0.53 in (2016) |
| September 6 | 98.1°F (1978) | 32.0°F (1998) | 0.67 in (2013) |
| September 7 | 105.1°F (2022) | 30.0°F (1965) | 1.30 in (2020) |
| September 8 | 102.0°F (2022) | 25.0°F (2020) | 0.70 in (1991) |
| September 9 | 98.1°F (2005) | 32.0°F (1992) | 0.87 in (1970) |
| September 10 | 97.0°F (1981) | 30.0°F (1965) | 0.36 in (2014) |
| September 11 | 95.0°F (1966) | 23.0°F (1964) | 0.80 in (2019) |
| September 12 | 97.0°F (1971) | 26.1°F (1975) | 1.56 in (2019) |
| September 13 | 93.0°F (1969) | 21.9°F (1970) | 1.18 in (1967) |
| September 14 | 91.0°F (1969) | 17.1°F (2007) | 1.10 in (1994) |
| September 15 | 96.1°F (2002) | 28.0°F (1999) | 1.25 in (2017) |
| September 16 | 91.9°F (1998) | 28.0°F (1973) | 0.30 in (2017) |
| September 17 | 98.1°F (1979) | 23.0°F (1965) | 1.45 in (2006) |
| September 18 | 98.1°F (2021) | 21.9°F (1991) | 1.30 in (1988) |
| September 19 | 96.1°F (2021) | 24.1°F (1965) | 1.63 in (1978) |
| September 20 | 93.0°F (1981) | 25.0°F (1983) | 1.44 in (2018) |
| September 21 | 89.1°F (2025) | 15.1°F (1995) | 0.58 in (1970) |
| September 22 | 88.0°F (2020) | 23.0°F (1983) | 0.95 in (2006) |
| September 23 | 93.9°F (1992) | 25.0°F (1993) | 0.81 in (2023) |
| September 24 | 93.9°F (1992) | 26.1°F (1985) | 0.41 in (1984) |
| September 25 | 93.9°F (2014) | 25.0°F (1984) | 2.34 in (1986) |
| September 26 | 93.0°F (2015) | 23.0°F (1965) | 0.31 in (2013) |
| September 27 | 91.0°F (1983) | 21.9°F (1976) | 1.13 in (1982) |
| September 28 | 91.0°F (2021) | 21.9°F (1972) | 0.44 in (1982) |
| September 29 | 98.1°F (2024) | 25.0°F (1972) | 0.50 in (1966) |
| September 30 | 95.0°F (2024) | 17.1°F (1985) | 0.52 in (1983) |