If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Colombo 06: The hottest months are usually March and April with an average temp of 81°F, while the coldest months are January and February with an average of 80°F. The rainiest months in Colombo 06 are May, October, June, and November, with each month seeing an average of 16 inches of rainfall.