Other facts from our historical weather data: Which is the warmest month in Maentwrog? 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 Maentwrog? The coldest month is February with an average maximum temperature of 8°C (46°F). Which is the wettest month in Maentwrog? December tops the wettest month list with 156mm (6.1 in) of rainfall. Which is the driest month in Maentwrog? April is the driest month with 95mm (3.7 in) of precipitation. Which is the sunniest month in Maentwrog? May is the sunniest month with an average of 169 hours of sunshine. 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.