Merthyr Tydfil in december: average Weather, Temperature and Climate
Weather in Merthyr Tydfil in december 2026
The weather in Merthyr Tydfil in the month of december comes from statistical datas on the past years. You can view the weather statistics for all the month, but also by clicking on the tabs for the beginning, the middle and the end of the month.
Average weather throughout december
very bad weather 126.5cm
Weather at 6am
43°F
Cloudy
29% of time
18%
17%
15%
Weather at 12pm
45°F
Cloudy
37% of time
17%
16%
16%
Weather at 6pm
43°F
Cloudy
26% of time
20%
18%
16%
Weather at 3am
43°F
20%
20%
18%
17%
Evolution of daily average temperature and precipitation in Merthyr Tydfil in december
These charts show the evolution of average minimum/maximum temperatures as well as average daily precipitation volume in Merthyr Tydfil in december.
The climate of Merthyr Tydfil in december is very bad
In december in Merthyr Tydfil, the climate is wet (with 5.3in of precipitation over 9 days). The weather is better from the previous month since in november it receives an average of 4.9in of precipitation over 9 days.
The climate is quite more than very fresh in that area december. Plan to cover you well! Temperatures are up to 47°F. On average, the recorded minimum temperature is 41°F. Thus, the mean temperature average in december in Merthyr Tydfil is 43°F. Note that seasonal normals in contrast with those observed in Merthyr Tydfil in the month of december with a maximum record of 56°F in 2015 and a minimum record of 22°F in 2010. You can expect to have about 4 days with temperatures below 32°F, or 13% of time.
Day length in Merthyr Tydfil in december is 07:49. Sunrise is at 08:14 and sunset is at 16:03.
Seasonal average climate and temperature of Merthyr Tydfil in december
Check below seasonal norms These datas are set from the weather statements of the last years of december.
| December | |||||
| Outside temperature | |||||
| Average temperature | 43°F | ||||
| Highest temperature | 47°F | ||||
| Lowest temperature | 41°F | ||||
| Highest record temperature | 56°F (2015) | ||||
| Lowest record temperature | 22°F (2010) | ||||
| Number of days at -32°F | 4 day(s) (13%) | ||||
| Wind | |||||
| Wind speed | 25km/h | ||||
| Wind temperature | 34°F | ||||
| Precipitation (rainfall) | |||||
| Rainfall | 5.3in | ||||
| Number of days with rainfall | 9 day(s) (28%) | ||||
| Record daily rainfall | 2.1in (2012) | ||||
| Snowfall | 126.5cm | ||||
| Other climate data | |||||
| Humidity | 93% | ||||
| Visibility | 8.28km | ||||
| Cloud cover | 65% | ||||
| UV index | 3 | ||||
| Daily sunshine hours | 6 | ||||
| Sunrise and sunset | |||||
| Time of sunrise | 08:14 | ||||
| Time of sunset | 16:03 | ||||
| Length of day | 07:49 | ||||
| Our opinion about the weather in december | |||||
| Our opinion at whereandwhen.net | very bad | ||||
How was the weather last december?
Here is the day by day recorded weather in Merthyr Tydfil in december 2025:
49°F to 50°F
40°F to 45°F
41°F to 45°F
38°F to 43°F
41°F to 49°F
45°F to 47°F
47°F to 54°F
49°F to 50°F
52°F to 54°F
47°F to 49°F
41°F to 49°F
41°F to 47°F
41°F to 45°F
45°F to 49°F
47°F to 49°F
40°F to 47°F
36°F to 47°F
45°F to 50°F
41°F to 45°F
40°F to 43°F
40°F to 45°F
43°F to 47°F
41°F to 45°F
36°F to 40°F
32°F to 36°F
31°F to 38°F
32°F to 41°F
36°F to 40°F
34°F to 40°F
36°F to 38°F
31°F to 38°F
Map: other cities in Wales in december
Cities near Merthyr Tydfil:
| Brecon Beacons (National Park) in december | very bad weather |
| Cardiff in december | bad weather |
| Porthcawl in december | bad weather |
| Barry in december | bad weather |
| Swansea in december | bad weather |
| Llanelli in december | bad weather |
| Llandrindod Wells in december | very bad weather |
| Carmarthen in december | bad weather |
| Newtown in december | very bad weather |
| Aberystwyth in december | bad weather |
| Pembrokeshire in december | bad weather |
| Haverfordwest in december | bad weather |
Click over cities on the map for information about the weather in december.
Merthyr Tydfil
perfect weather
good
tolerable
bad
very bad
Weather data for Merthyr Tydfil in december:
Weather data for Merthyr Tydfil for december are derived from an average of the weather forecast since 2009 in Merthyr Tydfil. There is a margin of error and these forecasts are to be considered as general information only. The weather in Merthyr Tydfil can vary slightly from year to year, but this data should limit surprises. So you can pack your bags or check for the best time in year to go to Merthyr Tydfil.