December weather in Riley, IN
The average temperature in Riley in December is 33.5°F (25.9°F–41.1°F). Average precipitation: 2.49 inches.
December is a winter month in Riley, and is cooler than the annual average of 53.5°F. Daily temperatures swing about 15.2°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 9h 14m. For travel, December is cold.
Avg High
41.1°F
Avg Low
25.9°F
Precipitation
2.49 in
Daylight
9h 14m
December records in Riley
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 62.1°F (2012) | 10.9°F (2002) | 0.89 in (2018) |
| December 2 | 64.0°F (2012) | 14.0°F (2005) | 0.69 in (2009) |
| December 3 | 72.0°F (2012) | 15.3°F (2006) | 0.11 in (2008) |
| December 4 | 69.1°F (1998) | 12.2°F (2006) | 0.47 in (2011) |
| December 5 | 66.9°F (1998) | 9.0°F (2025) | 1.30 in (2014) |
| December 6 | 73.0°F (1998) | 9.1°F (2010) | 0.60 in (1998) |
| December 7 | 61.0°F (2004) | 2.1°F (2013) | 0.97 in (2004) |
| December 8 | 60.1°F (2024) | 1.2°F (2010) | 0.79 in (2009) |
| December 9 | 63.0°F (2023) | 1.2°F (2010) | 0.48 in (2012) |
| December 10 | 68.0°F (2021) | 8.2°F (2013) | 0.44 in (1999) |
| December 11 | 68.0°F (2021) | 7.2°F (2013) | 0.94 in (2000) |
| December 12 | 70.0°F (2015) | -0.8°F (2013) | 1.40 in (2006) |
| December 13 | 66.9°F (2015) | 7.2°F (2010) | 0.97 in (2009) |
| December 14 | 68.0°F (2015) | -2.9°F (2025) | 1.03 in (2011) |
| December 15 | 64.0°F (2021) | -9.9°F (2025) | 0.29 in (2007) |
| December 16 | 62.1°F (2021) | 13.1°F (2009) | 0.74 in (1961) |
| December 17 | 60.1°F (2006) | -5.1°F (2000) | 0.72 in (2001) |
| December 18 | 59.0°F (2002) | -5.1°F (2000) | 1.01 in (2002) |
| December 19 | 55.9°F (2002) | 1.2°F (2016) | 0.72 in (2008) |
| December 20 | 60.1°F (2013) | -9.0°F (2000) | 0.71 in (2012) |
| December 21 | 55.0°F (2015) | -2.0°F (2000) | 2.29 in (2013) |
| December 22 | 55.9°F (2006) | -6.0°F (2000) | 0.60 in (2007) |
| December 23 | 64.0°F (2015) | -6.9°F (2022) | 1.08 in (2003) |
| December 24 | 64.9°F (2021) | -9.9°F (2004) | 0.37 in (2014) |
| December 25 | 66.0°F (2021) | -11.0°F (2000) | 0.47 in (2006) |
| December 26 | 66.9°F (2019) | -0.9°F (2000) | 0.93 in (2015) |
| December 27 | 69.1°F (2008) | -5.1°F (2004) | 1.54 in (2015) |
| December 28 | 68.0°F (2025) | -7.1°F (2000) | 1.68 in (2015) |
| December 29 | 62.1°F (2019) | 8.1°F (1961) | 1.48 in (2019) |
| December 30 | 57.9°F (2002) | 1.2°F (2012) | 0.86 in (2022) |
| December 31 | 62.1°F (2006) | -0.8°F (2017) | 1.33 in (2018) |