Tonga Surf Season, Surfing Conditions Tonga- Waterways Travel
The main island of Tongatapu is at 21° S latitude so the islands have two seasons which seem a little screwy to those from more temperate zones north of the equator. November to March is the summer north swell season, when swells from the North Pacific cross the equator and hit the exposed north and west shores of Tonga. During this time there are also swells from tropical cyclones in the South Pacific. During these summer months the prevailing winds are light east to southeast, although passing cyclones can create variable winds.
From April to October the Southern Hemisphere swells that surfers from Teahupoo to T Street live for sweep through Tonga on their way toward the equator. During this time the prevailing winds are southeast trades, which blow directly offshore at Ha’atafu Beach and groom all that raw swell energy to perfection.
Whatever season, Tonga is tropical. While it’s true that air and water temps are slightly cooler in Tonga than other South Pacific islands because Tonga is so close to the Tongan Trench, the deepest trench in the Pacific, that could be a blessing. Air temperatures range between 72° and 88° with the warmest months of January, February and March also measuring the most rainfall.
Water temperature doesn’t change much either and hovers at Just About Perfect: June and July may get as cool as 74 degrees, with December and January maxing at 80.