Cotati Weather in December
Average highs run from 60°F on December 1 to 57°F on December 31, and lows from 40°F to 38°F. Normal precipitation for the month is 5.19 in over about 12 wet days.
December day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
December at a glance
- Average high
- 58°F
- Average low
- 38°F
- Precipitation
- 5.19 in
- Record high
- 81°FDec 26, 1967
- Record low
- 16°FDec 14, 1932
- Chance of a freeze
- 84%
- Daylight
- 9 h 42 min to 9 h 32 min
- Cloud cover
- 58%
- Humidity
- 81%
- Dew point
- 39°F
- Wind
- 6.7 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation.
| Date | Normal high | Normal low | Record high | Record low | Chance wet |
|---|---|---|---|---|---|
| Dec 1 | 60°F | 40°F | 73°F 1929 | 24°F 1958 | 35% |
| Dec 2 | 60°F | 40°F | 75°F 2011 | 25°F 1922 | 35% |
| Dec 3 | 60°F | 39°F | 77°F 1927 | 26°F 1957 | 36% |
| Dec 4 | 60°F | 39°F | 75°F 1958 | 21°F 2013 | 36% |
| Dec 5 | 59°F | 39°F | 72°F 1976 | 25°F 1972 | 36% |
| Dec 6 | 59°F | 39°F | 73°F 1929 | 23°F 2013 | 37% |
| Dec 7 | 59°F | 39°F | 76°F 2020 | 23°F 2013 | 37% |
| Dec 8 | 59°F | 39°F | 75°F 1988 | 22°F 2009 | 37% |
| Dec 9 | 59°F | 39°F | 77°F 1934 | 19°F 1972 | 38% |
| Dec 10 | 58°F | 39°F | 74°F 1926 | 20°F 1932 | 38% |
| Dec 11 | 58°F | 39°F | 80°F 1958 | 19°F 1932 | 38% |
| Dec 12 | 58°F | 38°F | 78°F 1958 | 20°F 1932 | 38% |
| Dec 13 | 58°F | 38°F | 74°F 1926 | 19°F 1919 | 39% |
| Dec 14 | 58°F | 38°F | 74°F 1926 | 16°F 1932 | 39% |
| Dec 15 | 58°F | 38°F | 74°F 1926 | 17°F 1926 | 39% |
| Dec 16 | 58°F | 38°F | 73°F 1926 | 17°F 1926 | 39% |
| Dec 17 | 58°F | 38°F | 73°F 1926 | 19°F 1926 | 39% |
| Dec 18 | 57°F | 38°F | 75°F 1926 | 25°F 1924 | 39% |
| Dec 19 | 57°F | 38°F | 79°F 1999 | 20°F 1926 | 39% |
| Dec 20 | 57°F | 38°F | 75°F 1926 | 19°F 1926 | 39% |
| Dec 21 | 57°F | 38°F | 74°F 1926 | 19°F 1926 | 39% |
| Dec 22 | 57°F | 38°F | 74°F 1926 | 18°F 1926 | 39% |
| Dec 23 | 57°F | 38°F | 74°F 1926 | 22°F 1926 | 39% |
| Dec 24 | 57°F | 38°F | 69°F 1999 | 17°F 1926 | 39% |
| Dec 25 | 57°F | 38°F | 70°F 1972 | 21°F 1930 | 39% |
| Dec 26 | 57°F | 38°F | 81°F 1967 | 18°F 1926 | 39% |
| Dec 27 | 57°F | 38°F | 68°F 1917 | 19°F 1926 | 39% |
| Dec 28 | 57°F | 38°F | 76°F 1967 | 18°F 1926 | 39% |
| Dec 29 | 57°F | 38°F | 71°F 1967 | 20°F 1926 | 39% |
| Dec 30 | 57°F | 38°F | 71°F 1989 | 22°F 1930 | 39% |
| Dec 31 | 57°F | 38°F | 66°F 1995 | 18°F 1915 | 39% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (PST).
- December 1
- sunrise 7:09 AM, sunset 4:51 PM
- December 31
- sunrise 7:28 AM, sunset 5:00 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00046826 (Petaluma AP), public domain. Records: NOAA GHCN-Daily, station USC00046826, 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 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.