Cornwall Weather in December
Average highs run from 2°C on December 1 to -4°C on December 31, and lows from -5°C to -12°C. Normal precipitation for the month is 74 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
- -2°C
- Average low
- -9°C
- Precipitation
- 74 mm
- Reanalysis high
- 18°CDec 24, 2015
- Reanalysis low
- -38°CDec 27, 1993
- Daylight
- 9 h 02 min to 8 h 50 min
- Cloud cover
- 73%
- Humidity
- 90%
- Dew point
- -7°C
- Wind
- 11.5 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 | 2°C | -5°C | 13°C 1998 | -17°C 2007 | 49% |
| Dec 2 | 2°C | -6°C | 11°C 1998 | -17°C 2000 | 50% |
| Dec 3 | 1°C | -6°C | 10°C 2001 | -18°C 2002 | 49% |
| Dec 4 | 1°C | -6°C | 15°C 2012 | -15°C 2002 | 49% |
| Dec 5 | 1°C | -7°C | 15°C 1999 | -16°C 2003 | 47% |
| Dec 6 | 1°C | -7°C | 14°C 1998 | -17°C 2007 | 46% |
| Dec 7 | 0°C | -7°C | 16°C 1998 | -21°C 2000 | 46% |
| Dec 8 | 0°C | -8°C | 4°C 2015 | -26°C 1995 | 46% |
| Dec 9 | 0°C | -8°C | 8°C 2015 | -22°C 2000 | 45% |
| Dec 10 | -1°C | -8°C | 10°C 2015 | -17°C 1995 | 46% |
| Dec 11 | -1°C | -9°C | 13°C 2015 | -20°C 2008 | 45% |
| Dec 12 | -1°C | -9°C | 7°C 2015 | -22°C 1995 | 44% |
| Dec 13 | -2°C | -9°C | 9°C 1991 | -24°C 2000 | 44% |
| Dec 14 | -2°C | -10°C | 10°C 2015 | -22°C 1995 | 44% |
| Dec 15 | -2°C | -10°C | 10°C 2006 | -23°C 2004 | 44% |
| Dec 16 | -2°C | -10°C | 7°C 1992 | -24°C 2016 | 46% |
| Dec 17 | -2°C | -10°C | 9°C 2006 | -26°C 2013 | 46% |
| Dec 18 | -2°C | -10°C | 5°C 2006 | -23°C 2009 | 47% |
| Dec 19 | -2°C | -10°C | 5°C 2011 | -23°C 1991 | 47% |
| Dec 20 | -2°C | -10°C | 6°C 2002 | -31°C 2004 | 46% |
| Dec 21 | -3°C | -10°C | 7°C 2018 | -31°C 2004 | 47% |
| Dec 22 | -3°C | -10°C | 7°C 2015 | -23°C 2009 | 46% |
| Dec 23 | -3°C | -11°C | 8°C 2015 | -27°C 1993 | 46% |
| Dec 24 | -3°C | -11°C | 18°C 2015 | -27°C 1993 | 48% |
| Dec 25 | -3°C | -11°C | 12°C 2020 | -24°C 2013 | 47% |
| Dec 26 | -3°C | -11°C | 5°C 2015 | -29°C 1993 | 46% |
| Dec 27 | -3°C | -11°C | 7°C 2014 | -38°C 1993 | 48% |
| Dec 28 | -3°C | -11°C | 12°C 2008 | -30°C 1993 | 49% |
| Dec 29 | -3°C | -12°C | 6°C 2018 | -30°C 1993 | 49% |
| Dec 30 | -4°C | -12°C | 2°C 2003 | -23°C 2009 | 50% |
| Dec 31 | -4°C | -12°C | 7°C 2004 | -29°C 1997 | 50% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (EST).
- December 1
- sunrise 7:17 AM, sunset 4:19 PM
- December 31
- sunrise 7:37 AM, sunset 4:27 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.