Weather in Ushuaia in September

A hard month. September asks something of you. Go in knowing what. Highs sit at 6.2 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

September ranks 7 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 13 days, 0 of them heavy. Enough to need a plan B, not enough to need a plan around it. Layers, and a genuinely waterproof outer — at 6.2 °C the difference between a good day and a miserable one is entirely down to what you are wearing.

What the averages hide

Averages flatten a month, and this one hides a few things: 7 nights fall below freezing; the day barely swings — 4.9 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest September day reached 13.5 °C and the coldest night fell to -4.8 °C.

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 71 mm against 11 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 44 mm average is a reasonable planning figure, not a promise.

Wind sits around 18.1 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity runs at 87%, which at 6.2 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.

How September sits in the year

The month is on the way up: 2.6 °C warmer than August, and October adds another 2.2 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short.

Daylight in September

11.6 hours of daylight, gaining 2.2 hours across the month. That is between Ushuaia's extremes of 17.3 and 7.2 hours, so days are long enough not to constrain the plan.

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

Shoulder. The value months — prices ease off and you get the place closer to itself.

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

September in Ushuaia versus nearby

If Ushuaia is one option among several, the nearby comparison is worth making. Puerto Montt is a better bet in September — 6.5 °C warmer, 2 days more rain. Mar del Plata is a better bet in September — 7.3 °C warmer, 4 days less rain.

So: September works, with February the better month by 10 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 September.