Weather in Timaru in December

A good month. December is a solid month to be in Timaru. Highs average 18.3 °C, lows 12.1 °C, and rain falls on 12 days — nothing in the month is working against you.

December ranks 4 of 12 in Timaru: 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, 1 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. Across the twenty years measured, the hottest December day reached 27.5 °C and the coldest night fell to 6.9 °C, and the wettest single day dropped 39 mm — roughly 64% 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 128 mm against 21 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 61 mm average is a reasonable planning figure, not a promise.

Wind is light at 13.8 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 74%.

How December sits in the year

Temperatures hold steady either side: 16.4 °C in November, 18.3 here, 19.7 in January. Nothing about the timing within the month matters much.

Daylight in December

December is at or near the longest days of Timaru's year: 15.5 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 13.7 °C in December — too cold to swim without a wetsuit. The sea peaks at 15.3 °C in February and bottoms out at 9.4 °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, April is the trade worth considering — 14 points weaker on weather, and materially quieter.

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

December in Timaru versus nearby

If Timaru is one option among several, the nearby comparison is worth making. Christchurch is close enough to be a coin toss — 3.8 °C warmer, 2 days more rain. Waikowhai is the weaker option in December — within a degree on temperature, 5 days more rain.

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

Every month in Timaru

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