Fullerton weather in December: Fullerton, California: normal highs, lows, rain and records for December
Fullerton in December has a normal high of 68°F and a normal low of 46°F, a daily mean of 57°F, holding near 68°F all month. Measurable precipitation falls on 6 days in a normal December, 1.86 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 20°C and low of 8°C, 47 mm of precipitation in December.
- NOAA stationFullerton Municipal Airport
- Station IDUSW00003166
- Location33.87°N 117.98°W
- Elevation96 ft (29 m)
- From the center3 miles
- Population140,054
- Jan 69° 46°
- Feb 69° 48°
- Mar 71° 52°
- Apr 74° 54°
- May 76° 58°
- Jun 79° 63°
- Jul 84° 66°
- Aug 87° 66°
- Sep 85° 65°
- Oct 80° 58°
- Nov 74° 51°
- Dec 68° 46°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Fullerton in December?
The normal high is 68°F and the normal low 46°F, for a daily mean of 56.9°F. December is 5.5°F cooler than November and 0.7°F cooler than January. December is the 12th warmest month of the year in Fullerton and the 3rd wettest. Across the month the normal high falls 2°F, from 70°F on December 1 to 68°F on December 31. From one year to the next December's mean temperature typically moves about 1.6°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 55°F and 59°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 21%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 70°F | 47°F | 19% | 9% |
| December 8 | 68°F | 46°F | 20% | 10% |
| December 15 | 68°F | 45°F | 21% | 11% |
| December 22 | 68°F | 45°F | 20% | 11% |
| December 31 | 68°F | 46°F | 19% | 11% |
Every day of December: normal high, low and chance of precipitation (warmest afternoon December 1, coldest night December 16)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| December 1 | 70°F | 47°F | 19% | 9% | 10 h 10 min |
| December 2 | 69°F | 47°F | 19% | 9% | 10 h |
| December 3 | 69°F | 47°F | 19% | 9% | 10 h |
| December 4 | 69°F | 46°F | 19% | 9% | 10 h |
| December 5 | 69°F | 46°F | 19% | 9% | 10 h |
| December 6 | 69°F | 46°F | 20% | 9% | 10 h |
| December 7 | 68°F | 46°F | 20% | 10% | 10 h |
| December 8 | 68°F | 46°F | 20% | 10% | 10 h |
| December 9 | 68°F | 46°F | 20% | 10% | 10 h |
| December 10 | 68°F | 46°F | 20% | 10% | 10 h |
| December 11 | 68°F | 46°F | 20% | 10% | 10 h |
| December 12 | 68°F | 46°F | 20% | 10% | 10 h |
| December 13 | 68°F | 45°F | 20% | 10% | 10 h |
| December 14 | 68°F | 45°F | 21% | 10% | 10 h |
| December 15 | 68°F | 45°F | 21% | 11% | 10 h |
| December 16 | 68°F | 45°F | 21% | 11% | 9 h 50 min |
| December 17 | 68°F | 45°F | 21% | 11% | 9 h 50 min |
| December 18 | 68°F | 45°F | 21% | 11% | 9 h 50 min |
| December 19 | 68°F | 45°F | 20% | 11% | 9 h 50 min |
| December 20 | 68°F | 45°F | 20% | 11% | 9 h 50 min |
| December 21 | 68°F | 45°F | 20% | 11% | 9 h 50 min |
| December 22 | 68°F | 45°F | 20% | 11% | 9 h 50 min |
| December 23 | 68°F | 45°F | 20% | 11% | 9 h 50 min |
| December 24 | 68°F | 45°F | 20% | 11% | 9 h 50 min |
| December 25 | 68°F | 45°F | 20% | 11% | 9 h 50 min |
| December 26 | 68°F | 45°F | 20% | 11% | 9 h 50 min |
| December 27 | 68°F | 45°F | 19% | 11% | 9 h 50 min |
| December 28 | 68°F | 45°F | 19% | 11% | 9 h 50 min |
| December 29 | 68°F | 45°F | 19% | 11% | 9 h 50 min |
| December 30 | 68°F | 46°F | 19% | 11% | 10 h |
| December 31 | 68°F | 46°F | 19% | 11% | 10 h |
- Normal high
- 68°FDecember average
- Normal low
- 46°FDecember average
- Precipitation
- 1.86 inmonth total
- Days with precipitation
- 60.01 inch or more
- Daylight
- 10 h 10 min to 10 hDecember 1 to December 31
- Days at 70°F or more
- 12
- Days at 80°F or more
- 3
- Sunshine
- 83%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00003166; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Fullerton in December?
On a given December day the chance of 0.01 inch or more is 20% on average, highest around December 16 (21%). In all, 1.86 in falls on 6 days of a normal December.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00003166.
What are the records for December in Fullerton?
The warmest December temperature on this station's record (since 1998) is 87°F, on December 12, 2010; the coldest is 31°F, on December 24, 1998. The wettest December brought 9.22 in (2010).
The December mean against the 1991-2020 normal of 56.9°F: 2021 54.9°F (−2.0), 2022 57.1°F (+0.2), 2023 60.8°F (+3.9), 2024 58.1°F (+1.2), 2025 60.5°F (+3.6). 4 of 5 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 54.9°F | −2.0°F | 4.92 in |
| 2022 | 57.1°F | +0.2°F | 2.06 in |
| 2023 | 60.8°F | +3.9°F | 1.46 in |
| 2024 | 58.1°F | +1.2°F | 0.01 in |
| 2025 | 60.5°F | +3.6°F | 3.22 in |
Source: records: ACIS, station USW00003166; recent months: ACIS, station USW00003166. Records and recent months use complete months only.
How does December in Fullerton 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; Fullerton's is 68°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Fullerton in November74°F by day, 51°F at night
- Fullerton in January69°F by day, 46°F at night
- Fullerton 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