Vava'u has Tonga's wettest climate, with most rain falling in occasional tropical storms between late November and April, which is also the cyclone season. March is the wettest month, but gentle warm rains and occasional downpours occur at any time of year. Vava'u is generally warmer than Tongatapu, and although it can be particularly hot and sticky during the cyclone season, this can be a great time to visit, with fine days if you can stand the humidity.
The prevailing easterly and southeasterly trade winds blow at an average of 15 knots. Between November and April, both northerly and northwesterly winds can occur, usually accompanied by more unsettled seas which can impact on activities, such as sailing, diving and fishing on the western side of the group.