Weather in Wellington in December

A good month. December is a solid month to be in Wellington. Highs average 17.6 °C, lows 13.4 °C, and rain falls on 12 days — nothing in the month is working against you.

December ranks 4 of 12 in Wellington: past the worst of the year but short of February, which is the month to book if the dates are open.

Rain on 12 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 17.6 °C days and 13.4 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: the day barely swings — 4.1 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest December day reached 25 °C and the coldest night fell to 8.6 °C, and the wettest single day dropped 42 mm — roughly 61% of the month's rain in one day.

December is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest December on record still delivered 131 mm against 34 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 69 mm average is a reasonable planning figure, not a promise.

Wind sits around 19.6 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity runs at 81%, high enough to notice on the warm days without dominating them.

How December sits in the year

The month is on the way up: 2.1 °C warmer than November, and January adds another 1.6 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short.

Daylight in December

December is at or near the longest days of Wellington's year: 15.1 hours of daylight, holding steady all month. Evenings are the real gain — dinner outdoors still happens in full light.

Sea temperature

The sea sits at about 14.8 °C in December — cold — a quick dip rather than a swim, and a wetsuit if you are in for longer. The sea peaks at 16.8 °C in February and bottoms out at 11.6 °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

Busy. Popular without being frantic; book the things you care about, improvise the rest.

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

December in Wellington versus nearby

If Wellington is one option among several, the nearby comparison is worth making. Nelson is close enough to be a coin toss — 4.8 °C warmer, 2 days more rain. Palmerston North is close enough to be a coin toss — 3.3 °C warmer, 2 days more rain.

So: December works, with February the better month by 14 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Wellington

See all twelve months in Wellington, or where else to go in December.