September weather in Harlowton, MT
The average temperature in Harlowton in September is 56.1°F (39.6°F–72.5°F). Average precipitation: 1.07 inches.
September is a fall month in Harlowton, and is warmer than the annual average of 43.8°F. Daily temperatures swing about 32.9°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
72.5°F
Avg Low
39.6°F
Precipitation
1.07 in
Snow
0.1 in
September records in Harlowton
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 96.1°F (2016) | 33.1°F (1965) | 0.91 in (1953) |
| September 2 | 96.1°F (1950) | 30.0°F (1959) | 0.32 in (1975) |
| September 3 | 99.0°F (2022) | 30.0°F (1959) | 0.24 in (1999) |
| September 4 | 98.1°F (1998) | 27.0°F (1962) | 0.30 in (1957) |
| September 5 | 95.0°F (1998) | 25.0°F (1956) | 0.89 in (1993) |
| September 6 | 97.0°F (1980) | 30.0°F (1956) | 0.59 in (2002) |
| September 7 | 100.0°F (2022) | 30.9°F (2010) | 0.39 in (1971) |
| September 8 | 95.0°F (1998) | 28.0°F (1948) | 1.18 in (1970) |
| September 9 | 90.0°F (1982) | 19.0°F (1962) | 0.82 in (2001) |
| September 10 | 91.9°F (2017) | 27.0°F (1992) | 0.66 in (1965) |
| September 11 | 90.0°F (1954) | 19.9°F (1989) | 0.83 in (1978) |
| September 12 | 90.0°F (1953) | 23.0°F (1989) | 0.78 in (1993) |
| September 13 | 91.9°F (2017) | 21.0°F (1949) | 0.28 in (1967) |
| September 14 | 97.0°F (1948) | 17.1°F (1970) | 0.87 in (1982) |
| September 15 | 95.0°F (2000) | 25.0°F (1970) | 1.56 in (2017) |
| September 16 | 93.9°F (2000) | 21.9°F (2021) | 0.73 in (1959) |
| September 17 | 90.0°F (1998) | 16.0°F (1965) | 0.44 in (1977) |
| September 18 | 90.0°F (1981) | 12.9°F (1965) | 2.00 in (2024) |
| September 19 | 88.0°F (1956) | 23.0°F (1965) | 0.70 in (2000) |
| September 20 | 84.9°F (2025) | 23.0°F (1983) | 0.64 in (1968) |
| September 21 | 87.1°F (1967) | 24.1°F (1972) | 1.43 in (1959) |
| September 22 | 91.0°F (1987) | 19.0°F (1961) | 0.53 in (2023) |
| September 23 | 91.9°F (1987) | 23.0°F (1965) | 0.32 in (1984) |
| September 24 | 91.0°F (2011) | 21.0°F (2000) | 0.55 in (2005) |
| September 25 | 91.0°F (2024) | 19.9°F (1984) | 0.14 in (1972) |
| September 26 | 91.9°F (2015) | 19.9°F (1972) | 0.10 in (1950) |
| September 27 | 89.1°F (2021) | 14.0°F (1961) | 0.92 in (1982) |
| September 28 | 89.1°F (2022) | 14.0°F (1984) | 0.28 in (1982) |
| September 29 | 90.0°F (2024) | 14.0°F (1950) | 0.23 in (1983) |
| September 30 | 89.1°F (1992) | 10.0°F (1950) | 1.23 in (2022) |