Merthyr Tydfil Weather & Climate: Best Time to Visit

Visitors to Merthyr Tydfil can expect significant temperature changes throughout the year. Average maximum daytime temperatures range from a pleasant 20°C (68°F) in July, the warmest time of the year, to a chilly 8°C (46°F) during cooler months like January.

At night, you can expect temperatures ranging from 12°C (54°F) in July to around 2°C (36°F) during January.

Check out our detailed temperature page for more information.

Temperature ranges by month

Merthyr Tydfil is known for its substantial rain/snowfall, with annual precipitation reaching 1221 mm (48 in). Year-round, Merthyr Tydfil has a balanced climate with minimal variation in precipitation. The difference between the wettest month, October, with 122 mm (4.8 in), and the driest month, March, with 85 mm (3.3 in), is minimal. For more details, please visit our Merthyr Tydfil Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

Seasonal changes in sunshine hours are quite dramatic in Merthyr Tydfil. While July receives considerable daily sunshine with up to 6.7 hours, December marks the darkest time of the year, where sunshine is scarce with only 1.6 hours of sunlight per day.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

Daily percentage of sunshine

The city experiences its highest humidity in January, reaching 89%. In June, the humidity drops to its lowest level at 73%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year