Weather in Nuku‘alofa in September

A good month. September is a solid month to be in Nuku‘alofa. Highs average 23.3 °C, lows 22.3 °C, and rain falls on 12 days — nothing in the month is working against you.

Nuku‘alofa barely has seasons. September scores 77 out of 100 against a best of 78 in July — a gap small enough that the month you choose matters far less here than the week you choose.

Rain on 12 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average September reaches 30 °C; the day barely swings — 1 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest September day reached 25.8 °C and the coldest night fell to 19 °C, and the wettest single day dropped 44 mm — roughly 53% of the month's rain in one day.

September is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest September on record still delivered 155 mm against 29 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 83 mm average is a reasonable planning figure, not a promise.

Wind sits around 20.4 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity runs at 79%, high enough to notice on the warm days without dominating them.

How September sits in the year

Temperatures hold steady either side: 23 °C in August, 23.3 here, 24 in October. Nothing about the timing within the month matters much.

Daylight in September

11.9 hours of daylight, gaining 0.6 hours across the month. That is between Nuku‘alofa's extremes of 13.4 and 10.9 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 24.5 °C in September — warm enough to stay in as long as you like. The sea peaks at 28.1 °C in February and bottoms out at 24.3 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead. If the dates are flexible, May is the trade worth considering — 6 points weaker on weather, and materially quieter.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

September in Nuku‘alofa versus nearby

If Nuku‘alofa is one option among several, the nearby comparison is worth making. Apia is the weaker option in September — 5 °C warmer, 5 days more rain. Avarua is close enough to be a coin toss — within a degree on temperature, 2 days more rain.

So: September is effectively as good as it gets here — 1 points behind July, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Nuku‘alofa

See all twelve months in Nuku‘alofa, or where else to go in September.