Santa Rosa Weather in December
Average highs run from 30°C on December 1 to 32°C on December 31, and lows from 13°C to 16°C. Normal precipitation for the month is 99 mm over about 9 wet days.
December day by day
The normal high and low for each date, and the record, in °C.
- Normal low
- Normal high
- Record high
- Record low
December at a glance
- Average high
- 31°C
- Average low
- 15°C
- Precipitation
- 99 mm
- Record high
- 43°CDec 24, 1971
- Record low
- 2°CDec 8, 2001
- Daylight
- 14 h 29 min to 14 h 38 min
- Cloud cover
- 46%
- Humidity
- 48%
- Dew point
- 9°C
- Wind
- 9.0 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 | Record high | Record low | Chance wet |
|---|---|---|---|---|---|
| Dec 1 | 30°C | 13°C | 38°C 1977 | 5°C 1983 | 26% |
| Dec 2 | 30°C | 14°C | 37°C 1952 | 4°C 1970 | 25% |
| Dec 3 | 28°C | 13°C | 38°C 1998 | 4°C 2001 | 25% |
| Dec 4 | 28°C | 14°C | 38°C 1995 | 4°C 1971 | 25% |
| Dec 5 | 29°C | 13°C | 38°C 1995 | 4°C 1966 | 25% |
| Dec 6 | 29°C | 14°C | 40°C 2022 | 4°C 1999 | 26% |
| Dec 7 | 14°C | 39°C 1970 | 7°C 1971 | 26% | |
| Dec 8 | 30°C | 14°C | 39°C 1982 | 2°C 2001 | 27% |
| Dec 9 | 14°C | 41°C 1982 | 6°C 1963 | 25% | |
| Dec 10 | 31°C | 15°C | 41°C 2019 | 5°C 1985 | 24% |
| Dec 11 | 30°C | 15°C | 37°C 2022 | 6°C 1970 | 24% |
| Dec 12 | 30°C | 15°C | 38°C 1956 | 3°C 1970 | 24% |
| Dec 13 | 30°C | 15°C | 40°C 1961 | 5°C 1984 | 24% |
| Dec 14 | 31°C | 15°C | 39°C 2013 | 3°C 1958 | 24% |
| Dec 15 | 30°C | 15°C | 39°C 2022 | 5°C 1960 | 24% |
| Dec 16 | 16°C | 38°C 2013 | 5°C 2003 | 25% | |
| Dec 17 | 32°C | 15°C | 41°C 1995 | 6°C 1987 | 25% |
| Dec 18 | 32°C | 15°C | 40°C 1995 | 2°C 1954 | 26% |
| Dec 19 | 32°C | 15°C | 38°C 1962 | 5°C 1960 | 26% |
| Dec 20 | 15°C | 40°C 1995 | 5°C 1961 | 26% | |
| Dec 21 | 31°C | 15°C | 38°C 2011 | 7°C 1968 | 26% |
| Dec 22 | 30°C | 15°C | 38°C 1970 | 4°C 2014 | 26% |
| Dec 23 | 32°C | 15°C | 41°C 1994 | 5°C 1966 | 28% |
| Dec 24 | 33°C | 16°C | 43°C 1971 | 7°C 2011 | 30% |
| Dec 25 | 32°C | 16°C | 42°C 1971 | 5°C 1960 | 30% |
| Dec 26 | 17°C | 39°C 1982 | 8°C 1955 | 30% | |
| Dec 27 | 32°C | 18°C | 40°C 1971 | 7°C 1954 | 30% |
| Dec 28 | 32°C | 17°C | 41°C 2010 | 5°C 1964 | 31% |
| Dec 29 | 32°C | 17°C | 39°C 2013 | 9°C 1964 | 32% |
| Dec 30 | 33°C | 17°C | 41°C 2017 | 9°C 1958 | 33% |
| Dec 31 | 32°C | 16°C | 41°C 1994 | 6°C 1974 | 33% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (GMT-3).
- December 1
- sunrise 5:52 AM, sunset 8:21 PM
- December 31
- sunrise 6:01 AM, sunset 8:39 PM
Other months
Sources
Records: NOAA GHCN-Daily, station AR000087623, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: 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 2026-09-25. Sun and moon: computed with the NOAA solar equations and Meeus.