Dedham Weather in December
Average highs run from 45°F on December 1 to 36°F on December 31, and lows from 29°F to 21°F. Normal precipitation for the month is 5.39 in over about 13 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
- 40°F
- Average low
- 25°F
- Precipitation
- 5.39 in
- Snowfall
- 12.6 in
- Record high
- 77°FDec 7, 1998
- Record low
- -7°FDec 31, 2017
- Chance of a freeze
- 100%
- Daylight
- 9 h 19 min to 9 h 09 min
- Cloud cover
- 68%
- Humidity
- 85%
- Dew point
- 29°F
- Wind
- 6.5 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 | 45°F | 29°F | 72°F 2001 | 17°F 2007 | 39% | 11% |
| Dec 2 | 44°F | 29°F | 64°F 1998 | 11°F 1999 | 39% | 12% |
| Dec 3 | 44°F | 29°F | 70°F 2009 | 7°F 2000 | 39% | 12% |
| Dec 4 | 44°F | 28°F | 70°F 1998 | 8°F 2000 | 39% | 13% |
| Dec 5 | 43°F | 28°F | 68°F 2001 | 9°F 2000 | 39% | 13% |
| Dec 6 | 43°F | 28°F | 73°F 2001 | 4°F 2002 | 39% | 13% |
| Dec 7 | 43°F | 27°F | 77°F 1998 | 0°F 2002 | 40% | 14% |
| Dec 8 | 42°F | 27°F | 58°F 2022 | 7°F 2003 | 40% | 14% |
| Dec 9 | 42°F | 27°F | 62°F 2019 | -1°F 2003 | 40% | 15% |
| Dec 10 | 42°F | 27°F | 64°F 2019 | 1°F 2000 | 40% | 15% |
| Dec 11 | 41°F | 26°F | 67°F 2021 | 6°F 2016 | 40% | 15% |
| Dec 12 | 41°F | 26°F | 64°F 2021 | 9°F 2013 | 40% | 16% |
| Dec 13 | 41°F | 26°F | 63°F 2020 | 7°F 2000 | 40% | 16% |
| Dec 14 | 41°F | 25°F | 63°F 2019 | 0°F 2005 | 41% | 16% |
| Dec 15 | 40°F | 25°F | 64°F 2015 | -5°F 2005 | 41% | 17% |
| Dec 16 | 40°F | 25°F | 62°F 2021 | 4°F 2016 | 41% | 17% |
| Dec 17 | 40°F | 25°F | 66°F 2000 | -2°F 2013 | 41% | 18% |
| Dec 18 | 40°F | 24°F | 66°F 2023 | -5°F 2007 | 41% | 18% |
| Dec 19 | 39°F | 24°F | 60°F 2025 | 4°F 2020 | 41% | 18% |
| Dec 20 | 39°F | 24°F | 61°F 2002 | 5°F 2004 | 41% | 18% |
| Dec 21 | 39°F | 24°F | 67°F 2018 | 4°F 2004 | 41% | 19% |
| Dec 22 | 39°F | 23°F | 67°F 2013 | 8°F 2024 | 41% | 19% |
| Dec 23 | 38°F | 23°F | 61°F 2004 | -1°F 2009 | 42% | 19% |
| Dec 24 | 38°F | 23°F | 70°F 2015 | 9°F 1998 | 42% | 20% |
| Dec 25 | 38°F | 22°F | 67°F 2015 | 5°F 1998 | 42% | 20% |
| Dec 26 | 38°F | 22°F | 56°F 2015 | 2°F 2017 | 42% | 20% |
| Dec 27 | 37°F | 22°F | 59°F 2011 | -1°F 2017 | 42% | 21% |
| Dec 28 | 37°F | 22°F | 61°F 2008 | -1°F 2004 | 42% | 21% |
| Dec 29 | 37°F | 21°F | 58°F 2022 | -5°F 2017 | 42% | 21% |
| Dec 30 | 37°F | 21°F | 66°F 2022 | -3°F 2017 | 42% | 21% |
| Dec 31 | 36°F | 21°F | 57°F 2022 | -7°F 2017 | 42% | 22% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (EST).
- December 1
- sunrise 6:54 AM, sunset 4:13 PM
- December 31
- sunrise 7:13 AM, sunset 4:22 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00190736 (Blue Hill Coop), public domain. Records: NOAA GHCN-Daily, station USW00054704, 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.