Santa Rosa, CA weather in December
Santa Rosa is cool in December, with frequent rain: highs average 58°F and nights drop to about 37°F. Rain falls on about 13 days. It is one of the coolest months in Santa Rosa.
- Normal high
- 58°F
- Normal low
- 37°F
- Wet days
- 13
- 8.3 in total
- Muggy days
- 0
- dew point 65°F+
How December changes from start to finish
| December 1 | December 31 | |
|---|---|---|
| Normal high | 61°F | 57°F |
| Normal low | 38°F | 37°F |
| Chance of a wet day | 39% | 42% |
| Sunrise / sunset | 7:09 am / 4:50 pm | 7:27 am / 4:59 pm |
| Daylight | 9.7 h | 9.5 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 am41°Fdew point 38°F
- 9 am45°Fdew point 41°F
- Noon54°Fdew point 42°F
- 3 pm56°Fdew point 41°F
- 6 pm48°Fdew point 41°F
- 9 pm45°Fdew point 40°F
NOAA hourly normals (local standard time) from Travis AFB (44 mi away); average wind 7 mph; clear or few clouds in 48% of daytime hours, mostly cloudy or overcast in 45%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F5 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 snow13 of 31
- Notable rainat least 0.10 in9 of 31
- Freezing nightslow 32°F or below13 of 31
Average days per December, counted from daily records for each year 1991-2020.
Rain in December
Normal precipitation is 8.3 in; a dry December brings about 4.3 in and a wet one about 12.9 in (25th and 75th percentiles). About 6 days bring half an inch or more, and about 3 an inch or more. Snow is very rare.
How December varies from year to year
- Warmest December, 1991-20202013: average high 65°F
- Coolest December1994: average high 53°F
- Wettest December2005: 21.0 in
- Driest December2017: 0.05 in
- Highest reading81°F (December 3, 2011)
- Lowest reading18°F (December 9, 2013)
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 | 67°F | 58°F | 58°F |
| Normal low | 40°F | 37°F | 37°F |
| Wet days | 9 | 13 | 13 |
| Comfortable days | 18 | 5 | 7 |
| Daylight | 10.1 h | 9.5 h | 9.8 h |
Highs change by -9°F from November and 0°F into January.
Nearby alternatives in December
- Drier: Fairfield, CA39 mi · high 57°F · 10 wet days
- Cooler: South Lake Tahoe, CA151 mi · high 43°F · 11 wet days
How Santa Rosa ranks in December
- Normal high139th warmest of 378 cities; 44th of 60 in California
- Wet days328th driest of 378
- Comfortable days121st most of 340
What to pack for Santa Rosa in December
- A warm jacket – lows near 37°F, highs near 58°F
- A rain jacket or umbrella – rain on about 13 days
Frost in December
The first fall frost typically comes around Dec 1; in 1 year in 10 it comes before Nov 10. All frost dates for Santa Rosa.
Heating and cooling
December has 550 heating degree days and 0 cooling degree days (base 65°F), 17% of the year's total heating and cooling demand.
Questions
How cold is Santa Rosa in December?
The normal high is 58°F and the normal low is 37°F. From 1991 to 2020 the coldest December reading was 18°F (most recently on December 9, 2013).
Does it rain a lot in Santa Rosa in December?
About 13 days in December have at least 0.01 in of precipitation, and the normal total is 8.3 in. The wettest December in 1991-2020 was in 2005 (21.0 in); the driest was in 2017 (0.05 in).
Does it snow in Santa Rosa in December?
Snow is very rare: the 1991-2020 normal for December rounds to 0.0 in.
Is December a good time to visit Santa Rosa?
December ranks 12th of 12 months on our comfort score for Santa Rosa (46 out of 100). It has about 5 comfortable days. The best months are April and May.
Where the numbers come from
- Temperature and rain: Graton (USC00043578), 8.2 mi W of the city center, 200 ft . NOAA normals and daily records, 1991-2020.
- Snowfall, snow depth and frost dates: Santa Rosa (USC00047965), 1.1 mi N of the city center, 166 ft . NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Travis AFB (USW00023202), 44 mi ESE of the city center, 59 ft (106 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Sonoma County Airport (724957-23213), 6.8 mi NW of the city center, 119 ft . Hourly observations, 1991-2020.