If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Kathu: The hottest months are usually March and April with an average temp of 83°F, while the coldest months are January and February with an average of 81°F. The rainiest months in Kathu are September, October, July, and August, with each month seeing an average of 14 inches of rainfall.