The temperature increases from 23 to 27 °C (73.4 to 80.6 °F), and the annual rainfall is from 1,700 to 2,970 millimetres (66.9 to 116.9 inches) as one moves from Tongatapu in the south to the more northerly islands closer to the Equator. The average wettest period is around March with on average 263 mm (10.4 in). The average daily humidity is 80%.
The tropical cyclone season currently runs from 1 November to 30 April, though tropical cyclones can form and affect Tonga outside of the season.