December weather in Castlewood, SD
The average temperature in Castlewood in December is 17.8°F (8.7°F–26.9°F). Average precipitation: 0.53 inches.
December is a winter month in Castlewood, and is cooler than the annual average of 42.7°F. Daily temperatures swing about 18.2°F between overnight low and afternoon high. Daylight averages about 8h 38m. For travel, December is cold.
Avg High
26.9°F
Avg Low
8.7°F
Precipitation
0.53 in
Daylight
8h 38m
December records in Castlewood
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 46.0°F (2017) | -9.9°F (2014) | 0.21 in (2015) |
| December 2 | 53.1°F (2021) | -11.0°F (2014) | 0.56 in (2018) |
| December 3 | 57.0°F (2012) | -2.9°F (2022) | 0.02 in (2025) |
| December 4 | 52.0°F (2012) | -18.0°F (2025) | 0.02 in (2013) |
| December 5 | 46.0°F (2020) | -11.9°F (2025) | 0.05 in (2017) |
| December 6 | 46.0°F (2020) | -16.1°F (2013) | 0.00 in (2011) |
| December 7 | 55.9°F (2023) | -18.9°F (2013) | 0.07 in (2021) |
| December 8 | 59.0°F (2023) | -13.0°F (2013) | 0.03 in (2025) |
| December 9 | 50.0°F (2020) | -13.0°F (2013) | 0.09 in (2019) |
| December 10 | 52.0°F (2020) | -16.1°F (2012) | 0.10 in (2025) |
| December 11 | 46.9°F (2015) | -20.0°F (2013) | 0.04 in (2024) |
| December 12 | 42.1°F (2011) | -23.1°F (2016) | 0.01 in (2025) |
| December 13 | 44.1°F (2014) | -20.9°F (2016) | 0.35 in (2022) |
| December 14 | 50.0°F (2014) | -11.9°F (2016) | 0.18 in (2022) |
| December 15 | 52.0°F (2023) | -23.1°F (2016) | 0.10 in (2022) |
| December 16 | 46.9°F (2021) | -22.0°F (2016) | 0.59 in (2021) |
| December 17 | 44.1°F (2025) | -14.1°F (2016) | 0.05 in (2015) |
| December 18 | 42.1°F (2025) | -35.0°F (2016) | 0.15 in (2025) |
| December 19 | 52.0°F (2011) | -29.9°F (2016) | 0.09 in (2024) |
| December 20 | 41.0°F (2018) | -9.9°F (2022) | 0.02 in (2013) |
| December 21 | 39.0°F (2020) | -11.9°F (2012) | 0.04 in (2022) |
| December 22 | 46.0°F (2023) | -20.0°F (2022) | 0.13 in (2014) |
| December 23 | 54.0°F (2020) | -22.0°F (2013) | 0.02 in (2014) |
| December 24 | 48.0°F (2023) | -24.0°F (2013) | 1.05 in (2023) |
| December 25 | 41.0°F (2021) | -14.1°F (2022) | 0.38 in (2023) |
| December 26 | 41.0°F (2011) | -11.0°F (2017) | 3.00 in (2015) |
| December 27 | 45.0°F (2011) | -11.9°F (2017) | 0.36 in (2018) |
| December 28 | 46.0°F (2025) | -11.0°F (2017) | 0.64 in (2018) |
| December 29 | 46.0°F (2024) | -18.0°F (2018) | 0.31 in (2019) |
| December 30 | 50.0°F (2024) | -16.1°F (2014) | 0.26 in (2011) |
| December 31 | 37.0°F (2024) | -25.1°F (2017) | 0.18 in (2018) |