If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Port Coquitlam: The hottest months are usually August and July with an average temp of 61°F, while the coldest months are December and February with an average of 37°F. The rainiest months in Port Coquitlam are November, January, December, and October, with each month seeing an average of 12 inches of rainfall.