Why understand Ushuaia weather
Ushuaia is the southernmost city on the planet, and the weather here is unlike anything in your experience. In one day the temperature can change by 10–12 °C, sun gives way to snow, and the wind can reach storm-force gusts. If you're used to Moscow or St. Petersburg weather, imagine: Ushuaia summer is like a St. Petersburg June, only with Antarctic wind and an ozone hole overhead.
I live in Ushuaia and run tours year-round. In this article — precise figures by month, practical clothing advice, and some of the best information about UV radiation you won't find in typical guidebooks.
Temperature by month
| Month | Max °C | Min °C | Daylight | Season |
|---|---|---|---|---|
| January | +14 | +5 | ~17 h | Summer |
| February | +14 | +5 | ~16 h | Summer |
| March | +12 | +4 | ~13 h | Autumn |
| April | +9 | +2 | ~11 h | Autumn |
| May | +6 | 0 | ~9 h | Autumn |
| June | +4 | −1 | ~7.5 h | Winter |
| July | +4 | −1 | ~7 h 17 min | Winter |
| August | +5 | −1 | ~9 h | Winter |
| September | +7 | 0 | ~11 h | Spring |
| October | +9 | +2 | ~14 h | Spring |
| November | +11 | +3 | ~16 h | Spring |
| December | +13 | +5 | ~17 h | Summer |
For comparison: summer +14 °C — this is the level of July in Glasgow or Reykjavik. Winter +4/−1 °C is reminiscent of November in Oslo. Muscovites can think of late September — early October, only with strong wind.
Wind: the main factor
Average wind speed in Ushuaia — 23 km/h year-round. It's a constant, palpable airflow. But from November to January gusts reach 120 km/h — that's already storm-force.
What this means in practice:
- Felt temperature at +14 °C and wind 40 km/h — about +8 °C
- On the open water of the Beagle Channel the wind is stronger than in the city
- On the Laguna Esmeralda trail wind can hamper movement on open sections
- A windproof jacket isn't an option, it's a necessity any season
Precipitation
Annual average — 530 mm (for comparison: Moscow — 707 mm, St. Petersburg — 661 mm). Ushuaia is drier than it seems. But there are many rainy days: 14–17 per month. Precipitation falls in small amounts, often as drizzle or brief showers.
Snow in the city is possible from May to September. In the mountains — at the Martial Glacier and upper sections of the Laguna Esmeralda trek — snow lies from April to November.
The "four seasons in one day" phenomenon
This isn't an exaggeration. Documented temperature swings during a day are 10–12 °C. Morning may be +3 °C with frost, by noon — +14 °C with sun, by evening — back to +5 °C with rain.
Practical conclusion: dress in layers. Always. In any month.
Ozone hole and UV radiation: what guidebooks don't mention
This is the most important and most underestimated weather factor in Ushuaia. Each spring (September–November) the ozone layer over Antarctica and Tierra del Fuego thins. UV index in Ushuaia in October reaches 11.5 — this is the EXTREME category on the WHO scale.
For comparison: maximum UV in Moscow in summer — about 6. In Ushuaia in October UV is nearly twice as strong, at a temperature of just +9 °C. You don't feel the heat, but skin burns in 15–20 minutes.
Protection rules:
- SPF 50+ is mandatory from September to November, reapply every 2 hours
- Sunglasses with UV400 — year-round
- Wide-brimmed hat or face buff
- On the Laguna Esmeralda and Martial Glacier treks UV intensifies with altitude — protection is critical
Seasonal recommendations
Summer (December–February)
Best period for treks and boat trips. Long daylight (up to 17 h 20 min) allows planning packed routes. This is the ideal time for a Beagle Channel cruise, kayaking and helicopter excursions — maximum visibility and light.
Autumn (March–May)
Most beautiful colors — the beech forests of Tierra del Fuego National Park turn red and gold. Fewer tourists, lower prices. March is still comfortable for treks, May already requires winter gear.
Winter (June–August)
Ski season on Martial Glacier. Minimum tourist flow. Short daylight (7 h 17 min in July) limits activities, but the southern aurora (aurora australis) is sometimes visible. Full winter equipment needed.
Spring (September–November)
Snow melts, days lengthen, nature wakes up. But during this period the ozone hole is at maximum — UV protection is critical. Good time to observe sea lions and penguins in the Beagle Channel.
Clothing checklist
Summer (December–February)
- Thermal underwear (base layer)
- Fleece jacket (insulating layer)
- Wind- and waterproof jacket (shell)
- Trekking boots with ankle support
- Sunscreen SPF 50+
- UV400 sunglasses
- Hat or buff
- Gloves (for morning outings and sea trips)
Winter (June–August)
- Thermal underwear (merino wool)
- Insulated fleece or down sweater
- Winter jacket with membrane
- Insulated pants
- Winter boots
- Ice cleats / spikes (crampons)
- Warm gloves, hat, scarf
- Headlamp (short daylight)
Spring and autumn
- Layered clothing (all summer layers + additional insulation)
- SPF 50+ (especially September–November!)
- Rain jacket or membrane shell
- Trekking poles (trails can be slippery)
Frequently asked questions
When's the best time to come to Ushuaia?
For treks and boat excursions — December–February. For skiing — July–August. For photographing autumn colors — March–April. For minimum tourists and lower prices — May or September.
Is it really cold in summer in Ushuaia?
By Moscow standards — yes, +14 °C max. But with 17 hours of daylight and active outdoor time it's a comfortable temperature. The main enemy isn't cold, it's wind.
Do I need sunscreen in winter?
In winter the UV index is low (1–2), cream isn't required. But from September to November — absolutely necessary, UV reaches extreme values due to the ozone hole.
Are there windless days in Ushuaia?
Rarely. Average wind speed — 23 km/h. Completely windless days happen a few times a month and are considered a gift. Wind protection is needed always.
Can you trek in winter?
Yes, but with limitations. The Laguna Esmeralda trail is accessible with crampons. Martial Glacier works as a ski center. The national park is open, but some trails are closed due to snow. We run winter tours with appropriate gear.
What's the weather like on the Beagle Channel?
On the water it's always colder and windier than in the city. Even in summer, bring a warm jacket and hat on a boat trip. Water temperature — about +6 °C in summer.
How many rainy days per month?
From 14 to 17 — almost every other day. But rains are usually short, and fully washed-out days are rare. A waterproof jacket solves the problem.