Other facts from our historical weather data: Which is the warmest month in Bømlo? August has an average maximum temperature of 18°C (64°F) and is the warmest month of the year. Which is the coldest month in Bømlo? The coldest month is February with an average maximum temperature of 6°C (43°F). Which is the wettest month in Bømlo? October tops the wettest month list with 244mm (9.6 in) of rainfall. Which is the driest month in Bømlo? May is the driest month with 99mm (3.9 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.