Carmarthen Weather in December
Average highs run from 8°C on December 1 to 7°C on December 31, and lows from 5°C to 3°C. Normal precipitation for the month is 146 mm over about 19 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
- 7°C
- Average low
- 4°C
- Precipitation
- 146 mm
- Reanalysis high
- 13°CDec 19, 2015
- Reanalysis low
- -6°CDec 29, 1995
- Daylight
- 8 h 08 min to 7 h 51 min
- Cloud cover
- 82%
- Humidity
- 93%
- Dew point
- 5°C
- Wind
- 23.8 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 | 8°C | 5°C | 12°C 2006 | -2°C 2010 | 68% |
| Dec 2 | 8°C | 4°C | 12°C 2018 | -3°C 2010 | 66% |
| Dec 3 | 8°C | 4°C | 12°C 1994 | -3°C 2010 | 65% |
| Dec 4 | 8°C | 4°C | 12°C 2007 | 0°C 2016 | 63% |
| Dec 5 | 8°C | 4°C | 12°C 2001 | -2°C 1995 | 62% |
| Dec 6 | 8°C | 4°C | 13°C 2007 | -4°C 2010 | 61% |
| Dec 7 | 8°C | 4°C | 12°C 2015 | -6°C 2010 | 61% |
| Dec 8 | 8°C | 4°C | 12°C 2007 | -3°C 2010 | 62% |
| Dec 9 | 8°C | 4°C | 12°C 1997 | -2°C 1995 | 63% |
| Dec 10 | 8°C | 4°C | 13°C 1994 | -3°C 1991 | 63% |
| Dec 11 | 8°C | 4°C | 12°C 1994 | -3°C 1991 | 62% |
| Dec 12 | 8°C | 4°C | 12°C 1994 | -2°C 1991 | 62% |
| Dec 13 | 8°C | 4°C | 12°C 2003 | -1°C 2012 | 62% |
| Dec 14 | 7°C | 4°C | 12°C 1998 | -2°C 2001 | 62% |
| Dec 15 | 7°C | 4°C | 12°C 2015 | -2°C 2001 | 61% |
| Dec 16 | 7°C | 4°C | 12°C 2015 | -2°C 1997 | 61% |
| Dec 17 | 7°C | 4°C | 12°C 2015 | -2°C 1997 | 61% |
| Dec 18 | 7°C | 4°C | 12°C 2015 | -2°C 2010 | 62% |
| Dec 19 | 7°C | 4°C | 13°C 2015 | -4°C 2010 | 63% |
| Dec 20 | 7°C | 4°C | 11°C 2015 | -4°C 2010 | 63% |
| Dec 21 | 7°C | 4°C | 12°C 2015 | -5°C 2010 | 63% |
| Dec 22 | 7°C | 3°C | 12°C 2015 | -3°C 2010 | 64% |
| Dec 23 | 7°C | 3°C | 12°C 1997 | -3°C 2010 | 64% |
| Dec 24 | 7°C | 3°C | 12°C 1997 | -3°C 1992 | 64% |
| Dec 25 | 7°C | 3°C | 12°C 2015 | -4°C 2010 | 64% |
| Dec 26 | 7°C | 3°C | 12°C 2015 | -4°C 2010 | 62% |
| Dec 27 | 7°C | 3°C | 12°C 2015 | -3°C 1995 | 63% |
| Dec 28 | 7°C | 3°C | 12°C 1994 | -5°C 1995 | 62% |
| Dec 29 | 7°C | 3°C | 12°C 2006 | -6°C 1995 | 63% |
| Dec 30 | 7°C | 3°C | 12°C 2015 | -3°C 1995 | 63% |
| Dec 31 | 7°C | 3°C | 11°C 2017 | -4°C 1996 | 63% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (GMT).
- December 1
- sunrise 8:02 AM, sunset 4:10 PM
- December 31
- sunrise 8:25 AM, sunset 4:16 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 2026-09-25. Sun and moon: computed with the NOAA solar equations and Meeus.