September weather in Ketchum, ID
The average temperature in Ketchum in September is 52.6°F (36.1°F–69.0°F). Average precipitation: 1.01 inches.
September is a fall month in Ketchum, and is warmer than the annual average of 40.2°F. Daily temperatures swing about 32.9°F between overnight low and afternoon high. Expect about 4 days with precipitation. Daylight averages about 12h 17m. For travel, September is cool.
Avg High
69.0°F
Avg Low
36.1°F
Precipitation
1.01 in
Daylight
12h 17m
September records in Ketchum
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 87.1°F (1987) | 30.0°F (1975) | 0.16 in (1973) |
| September 2 | 86.0°F (1987) | 10.0°F (2012) | 0.49 in (1985) |
| September 3 | 89.1°F (1988) | 17.1°F (2012) | 0.59 in (2000) |
| September 4 | 90.0°F (1988) | 26.1°F (1980) | 0.59 in (2000) |
| September 5 | 88.0°F (1998) | 28.9°F (1975) | 0.95 in (1978) |
| September 6 | 90.0°F (2020) | 23.0°F (1975) | 1.65 in (1978) |
| September 7 | 89.1°F (2022) | 19.9°F (2008) | 1.28 in (1985) |
| September 8 | 90.0°F (2022) | 23.0°F (2010) | 0.59 in (1980) |
| September 9 | 86.0°F (2021) | 28.0°F (2010) | 1.20 in (1985) |
| September 10 | 82.0°F (1975) | 16.0°F (2010) | 1.18 in (1991) |
| September 11 | 82.9°F (2009) | 27.0°F (1983) | 1.14 in (1976) |
| September 12 | 84.9°F (1990) | 26.1°F (2012) | 0.91 in (1976) |
| September 13 | 84.0°F (1990) | 19.9°F (1992) | 0.52 in (2013) |
| September 14 | 82.9°F (2015) | 19.9°F (1992) | 0.77 in (2016) |
| September 15 | 82.0°F (1981) | 21.0°F (1992) | 0.46 in (2015) |
| September 16 | 82.9°F (1981) | 25.0°F (1985) | 0.35 in (2015) |
| September 17 | 84.0°F (1981) | 25.0°F (1987) | 0.37 in (2024) |
| September 18 | 82.0°F (1981) | 21.9°F (1996) | 0.84 in (1989) |
| September 19 | 79.0°F (1999) | 21.9°F (1975) | 0.40 in (2017) |
| September 20 | 78.1°F (2014) | -2.0°F (2010) | 0.53 in (2008) |
| September 21 | 77.0°F (1991) | 17.1°F (1983) | 0.22 in (1980) |
| September 22 | 80.1°F (1999) | 21.0°F (1991) | 1.09 in (2000) |
| September 23 | 82.0°F (1987) | 18.0°F (1996) | 0.33 in (2000) |
| September 24 | 82.9°F (1987) | 14.0°F (2008) | 0.54 in (2007) |
| September 25 | 81.0°F (1987) | 25.0°F (1993) | 0.40 in (1981) |
| September 26 | 82.0°F (2003) | 23.0°F (1981) | 0.39 in (2013) |
| September 27 | 80.1°F (2003) | 21.0°F (2008) | 0.56 in (1986) |
| September 28 | 78.1°F (2024) | 19.0°F (1985) | 0.25 in (1991) |
| September 29 | 78.1°F (1992) | 19.0°F (1985) | 0.25 in (1991) |
| September 30 | 78.1°F (1989) | 16.0°F (2009) | 1.60 in (2013) |