If you're looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Peradeniya: The hottest months are usually March and April, with an average temperature of 24°C, while the coldest months are January and February, with an average of 23°C. The rainiest months in Peradeniya are November, October, December and April, with each month seeing an average of 355 mm of rainfall.