Climate in Tonga

Tonga is a small territory, so travellers can expect the same climate wherever they stay. Conditions do not shift from one neighbourhood to the next, and the monthly figures given here apply throughout. One set of temperatures and rainfall totals is enough to plan a visit at any time of year. Expect the year to run from around -9°C at the cool end to 0°C when it is warmest. Those figures mark the usual seasonal contrast rather than a daily swing. Most months fall comfortably inside this range. Annual rainfall is close to 150mm. That is enough for visitors to expect some wet days in most seasons, even if the rain is seldom persistent. A light waterproof is a sensible addition to most itineraries. Rainfall is concentrated in the cooler months, when grey, damp days are more common than in summer. Travellers visiting in winter should expect wetter conditions and pack accordingly. The warmer season is comparatively drier and more settled.

March is the hottest month, with daytime highs around 0°C. Afternoons are typically the warmest part of the day, while mornings start cooler. Travellers visiting then can expect the year's most favourable temperatures for being outside. The lowest temperatures of the year occur in September, when overnight figures fall to around -9°C. Mornings can feel particularly cold until the sun is up. Extra layers are the main adjustment for a visit in this month. Averaged across all twelve months, the temperature is close to -2°C. This annual mean is a yearly summary, not a daily reading, with summer running warmer and winter cooler.

January is typically the wettest month, with a higher chance of rain than at any other time of year. Travellers visiting then should pack waterproofs as a matter of course. September and the surrounding months are usually the driest. Rain is less frequent then, though it is seldom absent altogether. Travellers looking for the most favourable window for outdoor plans often choose this part of the year. Winter snowfall averages around 150cm. Some years come in below that figure and some above, but snow is a genuine part of the cold season. Travellers visiting in winter should allow for icy pavements after a fall.