If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Nuku’alofa: The hottest months are usually February and March, with an average temperature of 27°C, while the coldest months are August and September, with an average of 23°C. The rainiest months in Nuku’alofa are February, March, January and April, with each month seeing an average of 291 mm of rainfall.