Climate ... and when to go
Tonga is further south than most Pacific nations which means it is a little cooler and receives less rain. But it is still sub-tropical and has 2 distinct seasons. The average temperature is 27C (80F), but during the wet season from December to April, temperatures will climb to 32C(90F) while from May to November, daytime temps could get as low as 23C (74F). Much of the heavy rainfall occurs at night and Tonga has high humidity all year round which is somewhat offset by the tradewinds.
In Vava’u temperatures range from 18C-25C (64F – 77F) between April and November and 24-32 (75F-90F) in the wet season between December and March. Trade winds are fairly constant between 13-18knots in the dry months.
The best times to go are in the dry season between April and November and most of the nation’s festivals are held during this period. Off season is during the Green season from December to March and some services like restaurants may have limited hours or even be closed.
If you are planning to travel at Christmas or school holiday periods, make sure you book well in advance as Tongans living abroad fill the flights.