Santa Rosa Weather in December
Average highs run from 35°C on December 1 to 35°C on December 31, and lows from 21°C to 23°C. Normal precipitation for the month is 146 mm over about 16 wet days.
December day by day
The normal high and low for each date, in °C.
- Normal low
- Normal high
- Reanalysis extreme high
- Reanalysis extreme low
December at a glance
- Average high
- 35°C
- Average low
- 22°C
- Precipitation
- 146 mm
- Reanalysis high
- 44°CDec 10, 2012
- Reanalysis low
- 14°CDec 13, 2010
- Daylight
- 13 h 28 min to 13 h 33 min
- Cloud cover
- 71%
- Humidity
- 59%
- Dew point
- 18°C
- Wind
- 12.2 km/h
Every day of the month
A wet day has at least 1 mm of precipitation in the reanalysis.
| Date | Normal high | Normal low | Reanalysis high | Reanalysis low | Chance wet |
|---|---|---|---|---|---|
| Dec 1 | 35°C | 21°C | 41°C 1999 | 15°C 2001 | 44% |
| Dec 2 | 35°C | 21°C | 43°C 2010 | 16°C 2018 | 44% |
| Dec 3 | 35°C | 21°C | 43°C 1994 | 15°C 2018 | 45% |
| Dec 4 | 35°C | 21°C | 43°C 1993 | 15°C 2001 | 46% |
| Dec 5 | 35°C | 22°C | 44°C 2013 | 14°C 1994 | 46% |
| Dec 6 | 35°C | 22°C | 43°C 2014 | 16°C 1999 | 46% |
| Dec 7 | 35°C | 22°C | 40°C 2014 | 16°C 1999 | 46% |
| Dec 8 | 35°C | 22°C | 41°C 2008 | 17°C 2018 | 46% |
| Dec 9 | 35°C | 22°C | 40°C 1991 | 17°C 2001 | 47% |
| Dec 10 | 35°C | 22°C | 44°C 2012 | 16°C 2003 | 48% |
| Dec 11 | 35°C | 22°C | 44°C 2010 | 18°C 2007 | 47% |
| Dec 12 | 35°C | 22°C | 42°C 2012 | 17°C 2010 | 47% |
| Dec 13 | 35°C | 22°C | 42°C 2015 | 14°C 2010 | 47% |
| Dec 14 | 35°C | 22°C | 43°C 2015 | 15°C 2010 | 48% |
| Dec 15 | 35°C | 22°C | 39°C 2004 | 16°C 2010 | 47% |
| Dec 16 | 35°C | 22°C | 42°C 1998 | 16°C 2016 | 45% |
| Dec 17 | 35°C | 22°C | 44°C 2015 | 15°C 2003 | 45% |
| Dec 18 | 35°C | 22°C | 43°C 2010 | 16°C 2017 | 45% |
| Dec 19 | 35°C | 22°C | 44°C 2010 | 18°C 2017 | 45% |
| Dec 20 | 35°C | 22°C | 40°C 1995 | 18°C 2016 | 46% |
| Dec 21 | 35°C | 22°C | 41°C 1999 | 19°C 2000 | 47% |
| Dec 22 | 35°C | 22°C | 41°C 2011 | 17°C 2014 | 48% |
| Dec 23 | 35°C | 23°C | 43°C 2015 | 18°C 2014 | 49% |
| Dec 24 | 35°C | 23°C | 42°C 2012 | 16°C 2014 | 51% |
| Dec 25 | 35°C | 23°C | 42°C 2016 | 16°C 2011 | 52% |
| Dec 26 | 35°C | 23°C | 42°C 2016 | 18°C 2011 | 53% |
| Dec 27 | 35°C | 23°C | 43°C 1997 | 16°C 2012 | 54% |
| Dec 28 | 35°C | 23°C | 42°C 1999 | 18°C 2012 | 52% |
| Dec 29 | 35°C | 23°C | 41°C 1997 | 17°C 2003 | 52% |
| Dec 30 | 35°C | 23°C | 41°C 2020 | 18°C 2003 | 54% |
| Dec 31 | 35°C | 23°C | 40°C 2016 | 20°C 1993 | 55% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (GMT-3).
- December 1
- sunrise 6:23 AM, sunset 7:51 PM
- December 31
- sunrise 6:34 AM, sunset 8:07 PM
Other months
Sources
Cloud, humidity, wind and sunshine, and temperature and precipitation: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.