Other facts from our historical weather data: Which is the warmest month in Coal Harbour? August has an average maximum temperature of 19°C (66°F) and is the warmest month of the year. Which is the coldest month in Coal Harbour? The coldest month is February with an average maximum temperature of 7°C (45°F). Which is the wettest month in Coal Harbour? November tops the wettest month list with 353mm (13.9 in) of rainfall. Which is the driest month in Coal Harbour? July is the driest month with 83mm (3.3 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.