September weather in Chinook, MT
The average temperature in Chinook in September is 56.8°F (41.2°F–72.3°F). Average precipitation: 0.99 inches.
September is a fall month in Chinook, and is warmer than the annual average of 42.4°F. Daily temperatures swing about 31.1°F between overnight low and afternoon high. Expect about 7 days with precipitation. Daylight averages about 12h 20m. For travel, September is a comfortable month to visit.
Avg High
72.3°F
Avg Low
41.2°F
Precipitation
0.99 in
Daylight
12h 20m
September records in Chinook
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 96.1°F (1945) | 30.0°F (1988) | 0.66 in (2008) |
| September 2 | 97.0°F (1945) | 30.0°F (1974) | 0.72 in (1915) |
| September 3 | 98.1°F (1998) | 30.9°F (1935) | 0.71 in (1900) |
| September 4 | 104.0°F (1998) | 28.9°F (1943) | 3.40 in (1911) |
| September 5 | 100.0°F (2022) | 23.0°F (1929) | 1.10 in (1911) |
| September 6 | 96.1°F (1931) | 26.1°F (1929) | 1.23 in (1911) |
| September 7 | 97.0°F (1957) | 30.0°F (1960) | 1.15 in (2020) |
| September 8 | 102.0°F (2022) | 25.0°F (1943) | 0.45 in (1946) |
| September 9 | 95.0°F (2017) | 26.1°F (1943) | 0.77 in (1921) |
| September 10 | 93.9°F (1998) | 25.0°F (1955) | 0.90 in (2010) |
| September 11 | 93.0°F (1958) | 18.0°F (1989) | 0.80 in (1961) |
| September 12 | 93.0°F (1958) | 23.0°F (1989) | 2.69 in (1978) |
| September 13 | 93.0°F (1913) | 21.0°F (1949) | 1.33 in (1967) |
| September 14 | 96.1°F (1946) | 28.0°F (1915) | 0.53 in (1917) |
| September 15 | 91.0°F (1948) | 25.0°F (1903) | 0.59 in (1906) |
| September 16 | 91.0°F (1998) | 23.0°F (1912) | 0.92 in (1988) |
| September 17 | 96.1°F (1939) | 28.0°F (1973) | 0.99 in (1904) |
| September 18 | 97.0°F (2009) | 19.0°F (1991) | 2.60 in (2024) |
| September 19 | 91.9°F (1981) | 21.0°F (1934) | 2.40 in (2024) |
| September 20 | 96.1°F (1922) | 21.0°F (1983) | 0.83 in (1947) |
| September 21 | 93.0°F (1938) | 12.9°F (1995) | 0.65 in (2018) |
| September 22 | 93.9°F (1938) | 21.9°F (1990) | 1.40 in (1945) |
| September 23 | 93.9°F (1992) | 19.9°F (1965) | 0.99 in (1904) |
| September 24 | 91.0°F (2011) | 18.0°F (1926) | 5.50 in (1986) |
| September 25 | 91.0°F (1952) | 16.0°F (1934) | 0.70 in (2013) |
| September 26 | 95.0°F (2001) | 17.1°F (1928) | 0.52 in (1908) |
| September 27 | 95.0°F (1922) | 16.0°F (1961) | 0.78 in (1982) |
| September 28 | 91.9°F (1967) | 15.1°F (1984) | 1.01 in (1954) |
| September 29 | 89.1°F (1967) | 15.1°F (1984) | 0.52 in (1977) |
| September 30 | 91.9°F (1963) | 18.0°F (1985) | 1.00 in (1950) |