If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Bentota: The hottest months are usually March and April, with an average temperature of 28°C, while the coldest months are January and February, with an average of 27°C. The rainiest months in Bentota are May, June, October and November, with each month seeing an average of 405 mm of rainfall.