Grass Valley weather in December: Grass Valley, California: normal highs, lows, rain and records for December
Grass Valley in December has a normal high of 53°F and a normal low of 33°F, a daily mean of 43°F, falling from 54°F on the 1st to 53°F by the 31st. Measurable precipitation falls on 12 days in a normal December, 10.48 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 11°C and low of 0°C, 266 mm of precipitation and 3 cm of snow in December.
- NOAA stationGrass Valley #2
- Station IDUSC00043573
- Location39.20°N 121.07°W
- Elevation2,400 ft (732 m)
- Population14,085
- Jan 54° 33°
- Feb 55° 34°
- Mar 58° 37°
- Apr 63° 40°
- May 71° 47°
- Jun 80° 53°
- Jul 88° 58°
- Aug 87° 57°
- Sep 82° 52°
- Oct 72° 44°
- Nov 60° 37°
- Dec 53° 33°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Grass Valley in December?
The normal high is 53°F and the normal low 33°F, for a daily mean of 42.6°F. December is 5.8°F cooler than November and 0.8°F cooler than January. December is the 12th warmest month of the year in Grass Valley and the wettest. Across the month the normal high falls 1°F, from 54°F on December 1 to 53°F on December 31. From one year to the next December's mean temperature typically moves about 1.8°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 41°F and 44°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 39%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 54°F | 34°F | 36% | 29% |
| December 8 | 53°F | 33°F | 38% | 30% |
| December 15 | 52°F | 32°F | 39% | 31% |
| December 22 | 52°F | 32°F | 39% | 31% |
| December 31 | 53°F | 32°F | 39% | 31% |
Every day of December: normal high, low and chance of precipitation (warmest afternoon December 1, coldest night December 20)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| December 1 | 54°F | 34°F | 36% | 29% | 9 h 40 min |
| December 2 | 54°F | 34°F | 37% | 29% | 9 h 40 min |
| December 3 | 54°F | 34°F | 37% | 29% | 9 h 40 min |
| December 4 | 54°F | 34°F | 37% | 29% | 9 h 30 min |
| December 5 | 53°F | 33°F | 38% | 30% | 9 h 30 min |
| December 6 | 53°F | 33°F | 38% | 30% | 9 h 30 min |
| December 7 | 53°F | 33°F | 38% | 30% | 9 h 30 min |
| December 8 | 53°F | 33°F | 38% | 30% | 9 h 30 min |
| December 9 | 53°F | 33°F | 38% | 30% | 9 h 30 min |
| December 10 | 53°F | 33°F | 39% | 31% | 9 h 30 min |
| December 11 | 53°F | 33°F | 39% | 31% | 9 h 30 min |
| December 12 | 52°F | 33°F | 39% | 31% | 9 h 30 min |
| December 13 | 52°F | 32°F | 39% | 31% | 9 h 30 min |
| December 14 | 52°F | 32°F | 39% | 31% | 9 h 30 min |
| December 15 | 52°F | 32°F | 39% | 31% | 9 h 30 min |
| December 16 | 52°F | 32°F | 39% | 31% | 9 h 30 min |
| December 17 | 52°F | 32°F | 39% | 31% | 9 h 30 min |
| December 18 | 52°F | 32°F | 39% | 31% | 9 h 20 min |
| December 19 | 52°F | 32°F | 39% | 31% | 9 h 20 min |
| December 20 | 52°F | 32°F | 39% | 31% | 9 h 20 min |
| December 21 | 52°F | 32°F | 39% | 31% | 9 h 20 min |
| December 22 | 52°F | 32°F | 39% | 31% | 9 h 20 min |
| December 23 | 52°F | 32°F | 39% | 31% | 9 h 20 min |
| December 24 | 52°F | 32°F | 39% | 31% | 9 h 20 min |
| December 25 | 52°F | 32°F | 39% | 31% | 9 h 20 min |
| December 26 | 52°F | 32°F | 39% | 31% | 9 h 20 min |
| December 27 | 52°F | 32°F | 39% | 31% | 9 h 30 min |
| December 28 | 52°F | 32°F | 39% | 31% | 9 h 30 min |
| December 29 | 52°F | 32°F | 39% | 31% | 9 h 30 min |
| December 30 | 53°F | 32°F | 39% | 31% | 9 h 30 min |
| December 31 | 53°F | 32°F | 39% | 31% | 9 h 30 min |
- Normal high
- 53°FDecember average
- Normal low
- 33°FDecember average
- Precipitation
- 10.48 inmonth total
- Days with precipitation
- 120.01 inch or more
- Snowfall
- 1.2 inmonth total
- Nights at 32°F or colder
- 17
- Daylight
- 9 h 40 min to 9 h 30 minDecember 1 to December 31
- Sunshine
- 69%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00043573; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Grass Valley in December?
On a given December day the chance of 0.01 inch or more is 39% on average, highest around December 31 (39%). In all, 10.48 in falls on 12 days of a normal December, 4 of them with an inch or more.
In a normal December in Grass Valley, 17 nights fall to freezing and snowfall averages 1.2 inches.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00043573.
What are the records for December in Grass Valley?
The warmest December temperature on this station's record (since 1966) is 80°F, on December 16, 1980; the coldest is 3°F, on December 10, 1972. The wettest December brought 27.81 in (1996); the snowiest, 16.8 inches (2021).
The December mean against the 1991-2020 normal of 42.6°F: 2021 41.5°F (−1.1), 2022 41.3°F (−1.3), 2023 46.4°F (+3.8), 2024 46.3°F (+3.7), 2025 48.2°F (+5.6). 3 of 5 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 41.5°F | −1.1°F | 16.56 in |
| 2022 | 41.3°F | −1.3°F | 19.23 in |
| 2023 | 46.4°F | +3.8°F | 5.36 in |
| 2024 | 46.3°F | +3.7°F | 12.19 in |
| 2025 | 48.2°F | +5.6°F | 13.38 in |
Source: records: ACIS, station USC00043573; recent months: ACIS, station USC00043573. Records and recent months use complete months only.
How does December in Grass Valley compare across California?
Across the 219 places PlainClimate covers in California, December normal highs run from 38°F in Tahoma to 71°F in Anaheim; Grass Valley's is 53°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Grass Valley in November60°F by day, 37°F at night
- Grass Valley in January54°F by day, 33°F at night
- Grass Valley through the yearEvery month, frost dates, records and recent years
- California in DecemberThe statewide normal and the warmest and coolest places
- Anaheim: California's warmest Decembernormal high 71°F