Weather in Ushuaia in December

A hard month. December asks something of you. Go in knowing what. You should expect rain on 21 days of the month, which is more days wet than dry.

December ranks 6 of 12 in Ushuaia: past the worst of the year but short of February, which is the month to book if the dates are open.

Rain on 21 of the month's 31 days, 1 of them heavy. At that frequency a wet-weather backup is not a contingency, it is the itinerary — book the indoor things first and treat the clear days as the bonus. Layers, and a genuinely waterproof outer — at 11.4 °C the difference between a good day and a miserable one is entirely down to what you are wearing.

What the averages hide

The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest December day reached 21.5 °C and the coldest night fell to 0.3 °C.

December is one of the reliable ones — rainfall has stayed between 46 mm and 107 mm across all twenty years, a narrow enough band that the 73 mm average is something you can plan against rather than merely quote.

Wind sits around 18.2 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity runs at 78%, which at 11.4 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.

How December sits in the year

Temperatures hold steady either side: 9.9 °C in November, 11.4 here, 12.2 in January. Nothing about the timing within the month matters much.

Daylight in December

December is at or near the longest days of Ushuaia's year: 17.3 hours of daylight, gaining 0.5 hours across the month. Evenings are the real gain — dinner outdoors still happens in full light.

An inland climate

Despite being inland, the year stays fairly even: 13.2 °C between the year's warmest afternoons and coldest nights.

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 — 8 points weaker on weather, and materially quieter.

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

December in Ushuaia versus nearby

If Ushuaia is one option among several, the nearby comparison is worth making. Puerto Montt is a better bet in December — 6.8 °C warmer, 10 days less rain. Mar del Plata is a better bet in December — 11.4 °C warmer, 10 days less rain.

So: December works, with February the better month by 8 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Ushuaia

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