Other facts from our historical weather data: Which is the warmest month in Betws-y-coed? 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 Betws-y-coed? The coldest month is February with an average maximum temperature of 8°C (46°F). Which is the wettest month in Betws-y-coed? December tops the wettest month list with 124mm (4.9 in) of rainfall. Which is the driest month in Betws-y-coed? May is the driest month with 88mm (3.5 in) of precipitation. Which is the sunniest month in Betws-y-coed? 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.