Sunnyvale weather in December: Sunnyvale, California: normal highs, lows, rain and records for December
Sunnyvale in December has a normal high of 59°F and a normal low of 42°F, a daily mean of 51°F, falling from 61°F on the 1st to 58°F by the 31st. Measurable precipitation falls on 11 days in a normal December, 2.51 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 15°C and low of 6°C, 64 mm of precipitation in December.
- NOAA stationMoffett Federal Airfield
- Station IDUSW00023244
- Location37.41°N 122.05°W
- Elevation39 ft (12 m)
- From the center2 miles
- Population156,792
- Jan 59° 42°
- Feb 62° 45°
- Mar 65° 47°
- Apr 68° 49°
- May 72° 53°
- Jun 76° 56°
- Jul 77° 59°
- Aug 77° 59°
- Sep 78° 57°
- Oct 74° 53°
- Nov 66° 46°
- Dec 59° 42°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Sunnyvale in December?
The normal high is 59°F and the normal low 42°F, for a daily mean of 50.5°F. December is 5.4°F cooler than November and 0.2°F cooler than January. December is the 12th warmest month of the year in Sunnyvale and the 2nd wettest. Across the month the normal high falls 3°F, from 61°F on December 1 to 58°F on December 31. From one year to the next December's mean temperature typically moves about 2.1°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 48°F and 53°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 35%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 61°F | 43°F | 32% | 16% |
| December 8 | 59°F | 42°F | 33% | 17% |
| December 15 | 59°F | 42°F | 34% | 19% |
| December 22 | 58°F | 42°F | 34% | 18% |
| December 31 | 58°F | 42°F | 35% | 18% |
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 | 61°F | 43°F | 32% | 16% | 9 h 50 min |
| December 2 | 61°F | 43°F | 32% | 16% | 9 h 50 min |
| December 3 | 60°F | 43°F | 33% | 16% | 9 h 50 min |
| December 4 | 60°F | 43°F | 33% | 17% | 9 h 40 min |
| December 5 | 60°F | 43°F | 33% | 17% | 9 h 40 min |
| December 6 | 60°F | 43°F | 33% | 17% | 9 h 40 min |
| December 7 | 60°F | 43°F | 33% | 17% | 9 h 40 min |
| December 8 | 59°F | 42°F | 33% | 17% | 9 h 40 min |
| December 9 | 59°F | 42°F | 33% | 18% | 9 h 40 min |
| December 10 | 59°F | 42°F | 34% | 18% | 9 h 40 min |
| December 11 | 59°F | 42°F | 34% | 18% | 9 h 40 min |
| December 12 | 59°F | 42°F | 34% | 18% | 9 h 40 min |
| December 13 | 59°F | 42°F | 34% | 18% | 9 h 40 min |
| December 14 | 59°F | 42°F | 34% | 18% | 9 h 40 min |
| December 15 | 59°F | 42°F | 34% | 19% | 9 h 40 min |
| December 16 | 59°F | 42°F | 34% | 19% | 9 h 40 min |
| December 17 | 59°F | 42°F | 34% | 19% | 9 h 40 min |
| December 18 | 58°F | 42°F | 34% | 19% | 9 h 40 min |
| December 19 | 58°F | 42°F | 34% | 19% | 9 h 40 min |
| December 20 | 58°F | 42°F | 34% | 19% | 9 h 40 min |
| December 21 | 58°F | 42°F | 34% | 18% | 9 h 30 min |
| December 22 | 58°F | 42°F | 34% | 18% | 9 h 30 min |
| December 23 | 58°F | 42°F | 34% | 18% | 9 h 30 min |
| December 24 | 58°F | 42°F | 34% | 18% | 9 h 30 min |
| December 25 | 58°F | 42°F | 34% | 18% | 9 h 40 min |
| December 26 | 58°F | 42°F | 34% | 18% | 9 h 40 min |
| December 27 | 58°F | 42°F | 34% | 18% | 9 h 40 min |
| December 28 | 58°F | 42°F | 35% | 18% | 9 h 40 min |
| December 29 | 58°F | 42°F | 35% | 18% | 9 h 40 min |
| December 30 | 58°F | 42°F | 35% | 18% | 9 h 40 min |
| December 31 | 58°F | 42°F | 35% | 18% | 9 h 40 min |
- Normal high
- 59°FDecember average
- Normal low
- 42°FDecember average
- Precipitation
- 2.51 inmonth total
- Days with precipitation
- 110.01 inch or more
- Nights at 32°F or colder
- 1
- Daylight
- 9 h 50 min to 9 h 40 minDecember 1 to December 31
- Days at 70°F or more
- 1
- Sunshine
- 74%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00023244; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Sunnyvale in December?
On a given December day the chance of 0.01 inch or more is 34% on average, highest around December 28 (35%). In all, 2.51 in falls on 11 days of a normal December, 1 of them with an inch or more.
In a normal December in Sunnyvale, 1 nights fall to freezing.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00023244.
What are the records for December in Sunnyvale?
The warmest December temperature on this station's record (since 1945) is 78°F, on December 5, 2003; the coldest is 23°F, on December 23, 1990. The wettest December brought 9.55 in (1955).
The December mean against the 1991-2020 normal of 50.5°F: 2025 52.7°F (+2.2). 1 of 1 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2025 | 52.7°F | +2.2°F | – |
Source: records: ACIS, station USW00023244; recent months: ACIS, station USW00023244. Records and recent months use complete months only.
How does December in Sunnyvale 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; Sunnyvale's is 59°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Sunnyvale in November66°F by day, 46°F at night
- Sunnyvale in January59°F by day, 42°F at night
- Sunnyvale 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