October weather in Keystone, SD
The average temperature in Keystone in October is 45.9°F (36.8°F–55.0°F). Average precipitation: 1.80 inches. Average snowfall is 4.9 inches.
October is a fall month in Keystone, and is warmer than the annual average of 45.7°F. Daily temperatures swing about 18.2°F between overnight low and afternoon high. Expect about 7 days with precipitation. Daylight averages about 10h 45m. For travel, October is cool.
Avg High
55.0°F
Avg Low
36.8°F
Precipitation
1.80 in
Snow
4.9 in
October records in Keystone
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| October 1 | 82.9°F (1992) | 23.0°F (1985) | 0.58 in (1982) |
| October 2 | 86.0°F (2011) | 25.0°F (1999) | 0.75 in (1998) |
| October 3 | 82.9°F (2025) | 26.1°F (1999) | 0.96 in (2022) |
| October 4 | 82.9°F (1963) | 27.0°F (2018) | 1.41 in (1998) |
| October 5 | 82.0°F (1963) | 23.0°F (2000) | 0.97 in (2009) |
| October 6 | 82.0°F (1975) | 18.0°F (2000) | 1.79 in (1994) |
| October 7 | 81.0°F (1975) | 21.0°F (1970) | 0.50 in (1970) |
| October 8 | 79.0°F (2020) | 19.9°F (1970) | 0.61 in (1997) |
| October 9 | 81.0°F (1963) | 10.0°F (2009) | 0.75 in (2001) |
| October 10 | 84.0°F (1976) | 6.1°F (2009) | 0.50 in (1983) |
| October 11 | 80.1°F (1975) | 10.0°F (2009) | 2.04 in (2013) |
| October 12 | 78.1°F (1991) | 10.0°F (2009) | 2.63 in (2023) |
| October 13 | 73.9°F (1963) | 16.0°F (1969) | 0.59 in (2007) |
| October 14 | 80.1°F (1964) | 15.1°F (1969) | 0.65 in (2013) |
| October 15 | 78.1°F (1964) | 18.0°F (1992) | 1.83 in (1980) |
| October 16 | 79.0°F (1991) | 16.0°F (1992) | 0.92 in (1994) |
| October 17 | 77.0°F (1991) | 21.0°F (1969) | 0.44 in (1988) |
| October 18 | 77.0°F (1963) | 17.1°F (2020) | 0.65 in (1971) |
| October 19 | 78.1°F (2003) | 16.0°F (1976) | 0.80 in (2021) |
| October 20 | 79.0°F (1974) | 17.1°F (2020) | 0.61 in (2019) |
| October 21 | 77.0°F (1992) | 18.0°F (2020) | 0.15 in (2008) |
| October 22 | 77.0°F (2003) | 17.1°F (2020) | 0.96 in (1995) |
| October 23 | 79.0°F (1973) | 12.0°F (2020) | 0.15 in (1986) |
| October 24 | 75.0°F (1978) | 8.1°F (2020) | 0.37 in (2012) |
| October 25 | 75.0°F (2007) | 3.0°F (2020) | 0.59 in (1996) |
| October 26 | 73.9°F (1966) | -4.0°F (2020) | 1.71 in (1996) |
| October 27 | 73.9°F (1983) | 10.9°F (2019) | 0.19 in (1989) |
| October 28 | 73.9°F (1990) | 8.1°F (1991) | 1.43 in (1998) |
| October 29 | 79.0°F (1968) | 3.9°F (2019) | 1.27 in (1996) |
| October 30 | 73.0°F (1968) | 1.0°F (1991) | 1.62 in (1974) |
| October 31 | 70.0°F (1999) | 9.0°F (1991) | 0.62 in (1992) |