December weather in Rancho Cucamonga, CA
The average temperature in Rancho Cucamonga in December is 55.2°F (43.6°F–66.9°F). Average precipitation: 1.89 inches.
December is a winter month in Rancho Cucamonga, and is cooler than the annual average of 66.8°F. Daily temperatures swing about 23.3°F between overnight low and afternoon high. Expect about 6 days with precipitation. Daylight averages about 9h 44m. For travel, December is a comfortable month to visit.
Avg High
66.9°F
Avg Low
43.6°F
Precipitation
1.89 in
Daylight
9h 44m
December records in Rancho Cucamonga
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 87.1°F (2021) | 32.0°F (2004) | 0.05 in (1998) |
| December 2 | 81.0°F (2020) | 30.9°F (2004) | 1.32 in (2014) |
| December 3 | 78.1°F (2007) | 37.0°F (2004) | 0.91 in (2014) |
| December 4 | 81.0°F (2007) | 34.0°F (2011) | 0.95 in (2019) |
| December 5 | 84.0°F (2023) | 34.0°F (2011) | 0.62 in (2018) |
| December 6 | 82.0°F (2024) | 32.0°F (2011) | 1.58 in (2018) |
| December 7 | 82.0°F (2006) | 32.0°F (2011) | 1.07 in (2009) |
| December 8 | 82.9°F (2015) | 33.1°F (1998) | 0.10 in (2004) |
| December 9 | 84.0°F (2017) | 35.1°F (2013) | 0.29 in (2006) |
| December 10 | 84.9°F (2017) | 31.1°F (2013) | 0.11 in (2015) |
| December 11 | 84.0°F (2025) | 34.0°F (1998) | 1.07 in (2022) |
| December 12 | 84.0°F (2010) | 36.0°F (2007) | 1.57 in (2014) |
| December 13 | 82.9°F (2017) | 36.0°F (2015) | 0.58 in (2012) |
| December 14 | 82.0°F (2017) | 35.1°F (2003) | 2.04 in (2021) |
| December 15 | 81.0°F (2013) | 32.0°F (2015) | 1.70 in (2008) |
| December 16 | 84.0°F (2013) | 33.1°F (2001) | 1.39 in (2002) |
| December 17 | 84.9°F (1998) | 36.0°F (2022) | 0.87 in (2008) |
| December 18 | 84.9°F (2024) | 33.1°F (2016) | 0.48 in (2010) |
| December 19 | 84.0°F (2024) | 33.1°F (2012) | 0.54 in (2010) |
| December 20 | 82.0°F (2020) | 33.1°F (2012) | 0.69 in (2002) |
| December 21 | 82.0°F (2005) | 33.1°F (2012) | 2.84 in (2010) |
| December 22 | 77.0°F (2014) | 28.0°F (1998) | 1.29 in (2010) |
| December 23 | 81.0°F (2014) | 28.0°F (1998) | 2.00 in (2021) |
| December 24 | 86.0°F (2005) | 28.9°F (1998) | 1.18 in (2025) |
| December 25 | 82.0°F (2013) | 30.9°F (1998) | 0.49 in (2008) |
| December 26 | 82.0°F (2013) | 32.0°F (2008) | 1.65 in (2019) |
| December 27 | 81.0°F (2013) | 32.0°F (2003) | 1.05 in (2021) |
| December 28 | 84.0°F (2017) | 30.9°F (2003) | 1.80 in (2020) |
| December 29 | 84.0°F (2017) | 32.0°F (2015) | 1.22 in (2004) |
| December 30 | 79.0°F (1998) | 34.0°F (2010) | 0.58 in (2021) |
| December 31 | 79.0°F (2011) | 30.2°F (2010) | 0.63 in (2004) |