Riverside, CA weather in December
December in Riverside: mild and mostly dry. Highs 67°F, lows 43°F, rain on about 4 days. It is one of the coolest months in Riverside. A good month for most outdoor plans.
- Normal high
- 67°F
- Normal low
- 43°F
- Wet days
- 4
- 1.4 in total
- Muggy days
- 0
- dew point 65°F+
How December changes from start to finish
| December 1 | December 31 | |
|---|---|---|
| Normal high | 69°F | 67°F |
| Normal low | 44°F | 43°F |
| Chance of a wet day | 11% | 16% |
| Sunrise / sunset | 6:36 am / 4:40 pm | 6:54 am / 4:50 pm |
| Daylight | 10.1 h | 9.9 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Pacific Time).
A typical December day
- 6 am42°Fdew point 32°F
- 9 am52°Fdew point 34°F
- Noon63°Fdew point 30°F
- 3 pm64°Fdew point 30°F
- 6 pm54°Fdew point 33°F
- 9 pm49°Fdew point 33°F
NOAA hourly normals (local standard time) from March AFB (9 mi away); average wind 5 mph; clear or few clouds in 61% of daytime hours, mostly cloudy or overcast in 31%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F17 of 31
- Hot dayshigh 90°F or more0 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow4 of 31
- Notable rainat least 0.10 in3 of 31
- Freezing nightslow 32°F or below1 of 31
Average days per December, counted from daily records for each year 1991-2020.
Rain in December
Normal precipitation is 1.4 in; a dry December brings about 0.5 in and a wet one about 1.8 in (25th and 75th percentiles). About 1 day brings half an inch or more. Snow is very rare.
How December varies from year to year
- Warmest December, 1991-20202017: average high 75°F
- Coolest December2012: average high 64°F
- Wettest December1992: 3.3 in
- Driest December2000: no measurable precipitation
- Highest reading87°F (December 17, 2013)
- Lowest reading25°F (December 24, 1998)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
December compared with November and January
| November | December | January | |
|---|---|---|---|
| Normal high | 75°F | 67°F | 68°F |
| Normal low | 47°F | 43°F | 44°F |
| Wet days | 2 | 4 | 5 |
| Comfortable days | 17 | 17 | 17 |
| Daylight | 10.4 h | 9.9 h | 10.2 h |
Highs change by -8°F from November and +1°F into January.
Nearby alternatives in December
- Cooler: Big Bear Lake, CA34 mi · high 46°F · 5 wet days
How Riverside ranks in December
- Normal high52nd warmest of 378 cities; 17th of 60 in California
- Wet days23rd driest of 378
- Comfortable days23rd most of 340
Frost in December
The first fall frost typically comes around Dec 30; in 1 year in 10 it comes before Dec 5. All frost dates for Riverside.
Heating and cooling
December has 318 heating degree days and 2 cooling degree days (base 65°F), 10% of the year's total heating and cooling demand.
Questions
How cold is Riverside in December?
The normal high is 67°F and the normal low is 43°F. From 1991 to 2020 the coldest December reading was 25°F (December 24, 1998).
Does it rain a lot in Riverside in December?
About 4 days in December have at least 0.01 in of precipitation, and the normal total is 1.4 in. The wettest December in 1991-2020 was in 1992 (3.3 in); the driest was in 2000, with no measurable precipitation.
Is December a good time to visit Riverside?
December ranks 6th of 12 months on our comfort score for Riverside (67 out of 100). It has about 17 comfortable days. The best months are March, April and May.
Where the numbers come from
- Temperature and frost dates: Riverside Muni Airport (USW00003171), 2.4 mi W of the city center, 805 ft . NOAA normals and daily records, 1991-2020.
- Rain, snowfall and snow depth: Riverside Fire Stn 3 (USC00047470), 0.5 mi ESE of the city center, 840 ft . NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: March AFB (USW00023119), 9.2 mi ESE of the city center, 1,516 ft (687 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: March Air Reserve Base (722860-23119), 9.2 mi ESE of the city center, 1,536 ft (707 ft higher than the city). Hourly observations, 1991-2020.