If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Mirissa: The hottest months are usually March and April, with an average temperature of 27°C, while the coldest months are January and February, with an average of 26°C. The rainiest months in Mirissa are November, May, October and December, with each month seeing an average of 259 mm of rainfall.