Weather in New Plymouth in December

A good month. December is a solid month to be in New Plymouth. Highs average 19.4 °C, lows 13.3 °C, and rain falls on 14 days — nothing in the month is working against you.

December ranks 5 of 12 in New Plymouth: past the worst of the year but short of January, which is the month to book if the dates are open.

Rain on 14 days, 4 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 December reaches 30 °C; the day barely swings — 6 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest December day reached 27.6 °C and the coldest night fell to 6.5 °C, and the wettest single day dropped 51 mm — roughly 47% 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 246 mm against 31 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 108 mm average is a reasonable planning figure, not a promise.

Wind is light at 14.4 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 83%, 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 1.7 °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 New Plymouth's year: 14.9 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 17.7 °C in December — cold — a quick dip rather than a swim, and a wetsuit if you are in for longer. The sea peaks at 20.2 °C in February and bottoms out at 14.2 °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, November is the trade worth considering — 12 points weaker on weather, and materially quieter.

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

December in New Plymouth versus nearby

If New Plymouth is one option among several, the nearby comparison is worth making. Taupo is close enough to be a coin toss — within a degree on temperature, 1 day less rain. Palmerston North is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: December works, with January the better month by 11 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in New Plymouth

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