Average temperature in December is 6.8 °C
Average daytime temperature is 8.5 °C
Average night temperature is 4.8 °C
Absolute maximum temperature: 11.7 °C
Absolute minimum temperature: -3.9 °C
Number of sunny days: 3
Number of rainy days: 27
Number of snow days: 1
Precipitation sum: 251 mm
* Weather data for Merthyr Tydfil United Kingdom is based on climate observations for 2023 year
| December (°C) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum temperature | 1.8 | 1.8 | 5.7 | 6.1 | 4.8 | 5.6 | 9.1 | 8.4 | 11.4 | 10.5 | 9.1 | 9.1 | 6.9 | 9.3 | 10 | 10.1 | 9 | 11 | 10.8 | 9.8 | 10.6 | 9.1 | 10 | 11.2 | 10.4 | 7.3 | 11.7 | 8.8 | 7.1 | 9.9 | 6.9 |
| Apparent max temperature | -1.8 | -1.4 | 3.2 | 4.3 | 1.8 | 0.4 | 6.3 | 4.8 | 7.4 | 6.3 | 6.2 | 7.1 | 3.8 | 6.6 | 7.7 | 7.5 | 5.1 | 7.8 | 9.4 | 6.1 | 6.1 | 4.2 | 5 | 8.4 | 6.6 | 5.5 | 6.5 | 3.4 | 2.9 | 4.6 | 2 |
| Mean temperature | -1.6 | -1.1 | 4.1 | 4.6 | 3 | 2.6 | 7.3 | 7.7 | 8.5 | 8.3 | 7.8 | 8.1 | 5 | 6.3 | 6.8 | 9.4 | 8.4 | 10 | 8.3 | 8.1 | 9.4 | 8.3 | 8.6 | 10.8 | 9.6 | 5.9 | 8.7 | 7.9 | 5.9 | 7 | 5.7 |
| Apparent mean temperature | -7.4 | -8 | -2.2 | -1.9 | -1.8 | -2.4 | 0.6 | 2.6 | 0.9 | 1.3 | 2.6 | 4 | -2.3 | -2.2 | 0.5 | 5.1 | 3 | 4.6 | 1.1 | 1.3 | 3 | 2.2 | 1.9 | 5.4 | 2.3 | 0.4 | 0.2 | 1.3 | -0.3 | -0.2 | -0.8 |
| Minimum temperature | -3.9 | -3.9 | 1.6 | 2.7 | 1.1 | 0.8 | 5.7 | 7 | 6.5 | 6.3 | 5.6 | 6.9 | 0.9 | 1 | 3.5 | 9.1 | 7.8 | 8.5 | 5.5 | 5.8 | 8 | 7.5 | 7.4 | 10.2 | 7.1 | 3.7 | 6 | 6.6 | 4.5 | 4.1 | 4 |
| Apparent min temperature | -5.1 | -4.8 | 1.4 | 1 | -0.6 | -1.2 | 3 | 3.7 | 3.7 | 3.5 | 4.2 | 5.3 | 1.1 | 3.6 | 3.9 | 5.9 | 3.9 | 6.4 | 5 | 3.6 | 4.4 | 3.4 | 3.4 | 6.6 | 5.7 | 2.4 | 3.7 | 2.2 | 1.6 | 2.9 | 0.6 |
| December | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight duration (h) | 8.2 | 8.1 | 8.1 | 8.1 | 8 | 8 | 8 | 8 | 7.9 | 7.9 | 7.9 | 7.9 | 7.9 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.9 |
| Sunshine duration (h) | 6.7 | 6.7 | 0 | 0 | 0.5 | 0 | 0 | 0 | 4 | 1 | 5.5 | 0 | 5.3 | 4.1 | 6 | 0 | 0 | 0 | 0.1 | 1 | 1.3 | 0 | 2.4 | 0 | 0.2 | 2.5 | 0 | 0 | 2 | 0 | 2.8 |
| Precipitation (mm) | 0 | 0.4 | 13.7 | 14.3 | 0.1 | 5.1 | 31.9 | 2 | 13.7 | 13.8 | 0.4 | 21.3 | 0 | 0.7 | 0.2 | 0.6 | 0 | 11.4 | 10.9 | 1 | 0.9 | 0.5 | 2.1 | 11.7 | 8.5 | 2.4 | 44 | 8.7 | 6.2 | 17.2 | 7.7 |
| Precipitation hours | 0 | 2 | 21 | 16 | 1 | 7 | 19 | 10 | 11 | 16 | 2 | 24 | 0 | 5 | 2 | 6 | 0 | 23 | 13 | 9 | 7 | 5 | 5 | 21 | 16 | 4 | 23 | 21 | 7 | 17 | 15 |
| Wind speed (m/s) | 9.3 | 14.4 | 16.2 | 21.1 | 18.7 | 28.2 | 30.2 | 26.4 | 36.7 | 42.3 | 33 | 21.5 | 24.6 | 18.4 | 16.6 | 28.4 | 31.1 | 27.9 | 24.8 | 28.9 | 36.3 | 32.6 | 36.5 | 39.9 | 28.6 | 28.3 | 42.9 | 43.8 | 27.1 | 37 | 37.1 |
In December 2023, the highest daytime temperature in Merthyr Tydfil was 11.7°C.
While the minimum temperature at night dropped to -3.9°C.
The average nighttime and daytime temperatures during December in Merthyr Tydfil are 4.8°C and 8.5°C respectively.
The precipitation sum in December is about 251 mm.