If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Bowen Island: The hottest months are usually August and July with an average temp of 58°F, while the coldest months are February and December with an average of 34°F. The rainiest months in Bowen Island are November, January, December, and October, with each month seeing an average of 17 inches of rainfall.