Other facts from our historical weather data: Which is the warmest month in Llanwrtyd Wells? July has an average maximum temperature of 19°C (66°F) and is the warmest month of the year. Which is the coldest month in Llanwrtyd Wells? The coldest month is February with an average maximum temperature of 7°C (45°F). Which is the wettest month in Llanwrtyd Wells? December tops the wettest month list with 131mm (5.2 in) of rainfall. Which is the driest month in Llanwrtyd Wells? April is the driest month with 92mm (3.6 in) of precipitation. No idea where to travel to this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.