Roy Weather in December
Average highs run from 47°F on December 1 to 45°F on December 31, and lows from 34°F to 33°F. Normal precipitation for the month is 5.99 in over about 20 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
- 45°F
- Average low
- 33°F
- Precipitation
- 5.99 in
- Snowfall
- 1.5 in
- Record high
- 67°FDec 10, 2014
- Record low
- 18°FDec 9, 2009
- Chance of a freeze
- 100%
- Daylight
- 8 h 48 min to 8 h 35 min
- Cloud cover
- 75%
- Humidity
- 93%
- Dew point
- 34°F
- Wind
- 5.1 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Dec 1 | 47°F | 34°F | 55°F 2012 | 24°F 2014 | 66% | 3% |
| Dec 2 | 46°F | 34°F | 56°F 2003 | 25°F 2022 | 66% | 3% |
| Dec 3 | 46°F | 34°F | 57°F 2007 | 31°F 2009 | 66% | 3% |
| Dec 4 | 46°F | 33°F | 61°F 2023 | 25°F 2013 | 66% | 3% |
| Dec 5 | 46°F | 33°F | 59°F 2023 | 26°F 2013 | 66% | 3% |
| Dec 6 | 46°F | 33°F | 54°F 2015 | 26°F 2013 | 66% | 3% |
| Dec 7 | 46°F | 33°F | 54°F 2024 | 21°F 2013 | 66% | 3% |
| Dec 8 | 45°F | 33°F | 58°F 2015 | 20°F 2009 | 66% | 3% |
| Dec 9 | 45°F | 33°F | 60°F 2014 | 18°F 2009 | 66% | 3% |
| Dec 10 | 45°F | 33°F | 67°F 2014 | 19°F 2009 | 66% | 3% |
| Dec 11 | 45°F | 33°F | 58°F 2014 | 21°F 2009 | 66% | 3% |
| Dec 12 | 45°F | 33°F | 60°F 2002 | 25°F 2009 | 66% | 3% |
| Dec 13 | 45°F | 33°F | 53°F 2002 | 27°F 2011 | 66% | 3% |
| Dec 14 | 45°F | 33°F | 61°F 2002 | 24°F 2008 | 66% | 3% |
| Dec 15 | 45°F | 33°F | 57°F 2025 | 24°F 2008 | 66% | 4% |
| Dec 16 | 45°F | 33°F | 55°F 2025 | 23°F 2008 | 66% | 4% |
| Dec 17 | 45°F | 33°F | 58°F 2024 | 24°F 2016 | 65% | 4% |
| Dec 18 | 45°F | 33°F | 58°F 2024 | 25°F 2008 | 65% | 4% |
| Dec 19 | 45°F | 33°F | 54°F 2024 | 22°F 2008 | 65% | 4% |
| Dec 20 | 45°F | 33°F | 58°F 2018 | 20°F 2008 | 65% | 4% |
| Dec 21 | 44°F | 33°F | 55°F 2014 | 23°F 2022 | 65% | 4% |
| Dec 22 | 45°F | 33°F | 54°F 2005 | 21°F 2022 | 65% | 4% |
| Dec 23 | 45°F | 33°F | 54°F 2024 | 25°F 2022 | 65% | 4% |
| Dec 24 | 45°F | 33°F | 57°F 2005 | 26°F 2020 | 65% | 4% |
| Dec 25 | 45°F | 33°F | 54°F 2005 | 29°F 2001 | 65% | 4% |
| Dec 26 | 45°F | 33°F | 58°F 2022 | 20°F 2021 | 65% | 4% |
| Dec 27 | 45°F | 33°F | 54°F 2022 | 18°F 2021 | 65% | 4% |
| Dec 28 | 45°F | 33°F | 54°F 2023 | 23°F 2021 | 65% | 4% |
| Dec 29 | 45°F | 33°F | 59°F 2023 | 25°F 2021 | 65% | 4% |
| Dec 30 | 45°F | 33°F | 52°F 2022 | 25°F 2010 | 65% | 4% |
| Dec 31 | 45°F | 33°F | 51°F 2019 | 18°F 2021 | 65% | 4% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PST).
- December 1
- sunrise 7:35 AM, sunset 4:23 PM
- December 31
- sunrise 7:56 AM, sunset 4:31 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00455224 (Mcmillin Rsvr), public domain. Records: NOAA GHCN-Daily, station USW00094274, 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.