September weather in Swan Valley, ID
The average temperature in Swan Valley in September is 55.9°F (37.4°F–74.5°F). Average precipitation: 1.55 inches.
September is a fall month in Swan Valley, and is warmer than the annual average of 42.6°F. Daily temperatures swing about 37.1°F between overnight low and afternoon high. Expect about 8 days with precipitation. Daylight averages about 12h 17m. For travel, September is cool.
Avg High
74.5°F
Avg Low
37.4°F
Precipitation
1.55 in
Daylight
12h 17m
September records in Swan Valley
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 100.0°F (2022) | 27.0°F (1962) | 0.47 in (1970) |
| September 2 | 99.0°F (2022) | 25.0°F (1974) | 0.53 in (2006) |
| September 3 | 96.1°F (2022) | 26.1°F (1981) | 0.62 in (2013) |
| September 4 | 102.9°F (2022) | 24.1°F (1969) | 0.70 in (2023) |
| September 5 | 98.1°F (2022) | 28.9°F (2014) | 1.15 in (2007) |
| September 6 | 99.0°F (2022) | 25.0°F (2015) | 0.77 in (2002) |
| September 7 | 100.0°F (2022) | 27.0°F (2015) | 1.08 in (2002) |
| September 8 | 102.0°F (2022) | 21.0°F (1976) | 0.89 in (2020) |
| September 9 | 91.0°F (1988) | 19.0°F (1962) | 0.45 in (2013) |
| September 10 | 93.0°F (2021) | 25.0°F (1964) | 1.26 in (1969) |
| September 11 | 93.9°F (1990) | 23.0°F (1964) | 0.63 in (1978) |
| September 12 | 93.0°F (1990) | 18.0°F (1988) | 0.65 in (1985) |
| September 13 | 91.0°F (2022) | 19.0°F (1974) | 0.70 in (1982) |
| September 14 | 95.0°F (1990) | 21.9°F (1974) | 0.52 in (1998) |
| September 15 | 96.1°F (1990) | 19.9°F (1970) | 0.73 in (2017) |
| September 16 | 88.0°F (2000) | 18.0°F (1971) | 0.66 in (2015) |
| September 17 | 89.1°F (1981) | 15.1°F (1971) | 0.44 in (1960) |
| September 18 | 88.0°F (2020) | 16.0°F (1971) | 1.30 in (1961) |
| September 19 | 87.1°F (1984) | 8.1°F (1983) | 1.68 in (1969) |
| September 20 | 84.9°F (1962) | 10.9°F (1983) | 1.00 in (1963) |
| September 21 | 86.0°F (2022) | 17.1°F (1995) | 0.93 in (1961) |
| September 22 | 88.0°F (1987) | 19.9°F (1971) | 1.87 in (2006) |
| September 23 | 89.1°F (1987) | 18.0°F (1985) | 0.52 in (2016) |
| September 24 | 89.1°F (1987) | 21.0°F (1961) | 0.86 in (2016) |
| September 25 | 87.1°F (2001) | 16.0°F (1970) | 0.30 in (2013) |
| September 26 | 88.0°F (2024) | 19.0°F (1970) | 1.14 in (1982) |
| September 27 | 84.9°F (2001) | 18.0°F (1964) | 0.62 in (1972) |
| September 28 | 88.0°F (2005) | 15.1°F (1999) | 0.83 in (2014) |
| September 29 | 91.0°F (2024) | 8.1°F (1985) | 1.00 in (1961) |
| September 30 | 90.0°F (2024) | 9.0°F (1985) | 0.71 in (1971) |