September weather in Plains, MT
The average temperature in Plains in September is 57.7°F (39.4°F–76.0°F). Average precipitation: inches.
September is a fall month in Plains, and is warmer than the annual average of 46.2°F. Daily temperatures swing about 36.6°F between overnight low and afternoon high. Daylight averages about 12h 19m. For travel, September is a comfortable month to visit.
Avg High
76.0°F
Avg Low
39.4°F
Precipitation
in
Daylight
12h 19m
September records in Plains
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 100.0°F (1967) | 28.9°F (2006) | 0.64 in (1986) |
| September 2 | 95.0°F (1967) | 27.0°F (1973) | 0.64 in (1968) |
| September 3 | 99.0°F (1967) | 28.9°F (1981) | 0.53 in (1997) |
| September 4 | 96.1°F (1967) | 24.1°F (1962) | 0.87 in (1994) |
| September 5 | 99.0°F (1967) | 28.0°F (1962) | 0.17 in (1977) |
| September 6 | 99.0°F (1967) | 28.0°F (1983) | 0.88 in (1985) |
| September 7 | 95.0°F (1963) | 24.1°F (1994) | 0.26 in (1995) |
| September 8 | 93.9°F (1963) | 24.1°F (1962) | 0.39 in (1995) |
| September 9 | 96.1°F (1981) | 21.9°F (1962) | 1.70 in (1986) |
| September 10 | 93.9°F (1963) | 28.0°F (1972) | 0.55 in (1995) |
| September 11 | 93.9°F (1963) | 27.0°F (1964) | 0.67 in (1962) |
| September 12 | 93.9°F (1963) | 26.1°F (1988) | 0.50 in (2003) |
| September 13 | 91.9°F (1981) | 16.0°F (1994) | 0.32 in (1966) |
| September 14 | 90.0°F (1981) | 19.0°F (1970) | 0.75 in (1996) |
| September 15 | 91.9°F (1998) | 19.0°F (1970) | 1.61 in (1965) |
| September 16 | 91.0°F (2009) | 21.0°F (1970) | 0.49 in (1963) |
| September 17 | 93.9°F (1981) | 19.9°F (1965) | 0.50 in (1977) |
| September 18 | 95.0°F (1981) | 19.0°F (1971) | 1.10 in (1986) |
| September 19 | 99.0°F (1981) | 21.0°F (1978) | 0.45 in (1995) |
| September 20 | 89.1°F (1967) | 26.1°F (1978) | 0.35 in (1986) |
| September 21 | 93.0°F (1967) | 19.9°F (1971) | 0.68 in (2008) |
| September 22 | 91.9°F (1967) | 24.1°F (1971) | 0.78 in (1977) |
| September 23 | 90.0°F (1966) | 17.1°F (2000) | 0.57 in (1984) |
| September 24 | 91.9°F (2001) | 19.9°F (2000) | 0.86 in (1992) |
| September 25 | 91.0°F (1967) | 19.0°F (1993) | 0.32 in (1973) |
| September 26 | 89.1°F (1963) | 23.0°F (1993) | 0.08 in (1969) |
| September 27 | 89.1°F (1963) | 18.0°F (1961) | 0.56 in (1988) |
| September 28 | 98.1°F (1987) | 19.9°F (1984) | 0.80 in (1982) |
| September 29 | 93.0°F (1967) | 18.0°F (1985) | 0.64 in (1977) |
| September 30 | 89.1°F (1963) | 19.9°F (1985) | 0.67 in (2005) |