Las Leñas Sees Rain on 1% of Winter Days. Mount Baw Baw Sees It on 43%. We Measured Southern-Hemisphere Snow Quality.

Snowfall totals tell you how much. They do not tell you what kind.

We built a snow-quality measure for Japan — how cold the snow falls, how often, how much rain interrupts it, how hard the wind blows while it does. We have now run the same measurement on all 55 ski areas below the equator. As far as we can tell, nobody has published this in English before.

The single most separating number is rain.

	Ski areas	Rain on this share of winter days
🇯🇵 Japan	395	16%
🇦🇷 Argentina	13	19%
🇨🇱 Chile	7	30%
🇳🇿 New Zealand	25	32%
🇦🇺 Australia	10	38%

Argentina’s typical ski area sees less winter rain than Chile’s, New Zealand’s or Australia’s, and is close to Japan’s. At the top of the Argentinian list it is not close at all:

	Rain days	Snow-day temperature
Las Leñas 🇦🇷	1%	−3.2 °C
Los Penitentes 🇦🇷	1%	−2.7 °C
Los Puquios 🇦🇷	1%	−1.1 °C
Portillo 🇨🇱	2%	−3.4 °C
Valle Nevado 🇨🇱	3%	−5.3 °C
—
Whakapapa 🇳🇿	51%	−3.3 °C
Pucón 🇨🇱	58%	−1.1 °C
Volcán Osorno 🇨🇱	65%	−2.8 °C

Las Leñas gets rain on one winter day in a hundred. Whakapapa gets it on one in two.

This is the difference between the high central Andes and everywhere else in the southern hemisphere. Las Leñas, Portillo, Penitentes and Valle Nevado sit between 2,600 m and 3,200 m in a dry continental band between 32°S and 35°S. Everything else on the southern list — the Chilean and Argentinian lake districts, the Southern Alps of New Zealand, the Australian ranges — is maritime, lower, and warmer.

Las Leñas beats 351 of Japan’s 395 ski areas

Ranking all 450 ski areas we have now measured for quality:

	Ski area		Score
1	Daisetsuzan Sounkyo Kurodake	🇯🇵	49.4
2	Asahidake	🇯🇵	45.9
3	Tengendai Kogen	🇯🇵	41.1
4	Chisennupri	🇯🇵	40.0
5	Shiga Kogen Shibutoge	🇯🇵	39.4
…
45	Las Leñas	🇦🇷	22.1
79	Portillo	🇨🇱	17.4
97	Valle Nevado	🇨🇱	15.6
108	Invincible Snowfields	🇳🇿	14.1

Only 44 Japanese ski areas score higher than Las Leñas. The other 351 score lower.

That is a real result and it needs one immediate caveat: this pool is 88% Japanese, so “45th of 450” is not a world ranking. What it means precisely is that Las Leñas would place in the top 45 if dropped into Japan — which is the comparison a skier choosing between a July trip to Argentina and a February trip to Japan actually wants.

The top of the list stays Japanese, and stays Hokkaido and the high inland ranges. Nothing in the southern hemisphere approaches Kurodake’s −11 °C. Las Leñas is dry because it barely rains, not because it is especially cold.

The snowiest southern resorts are mostly not the best ones

This is the same divergence we found in Japan between quantity and quality, and it is sharper below the equator.

Ski area		Snowfall	Quality
Corralco	🇨🇱	620 cm — 29th in the world	244th of 450
Antillanca	🇨🇱	534 cm — 60th	262nd
Batea Mahuida	🇦🇷	385 cm — 199th	348th
Cerro Bayo	🇦🇷	372 cm — 235th	352nd
Treble Cone	🇳🇿	337 cm — 341st	266th

Corralco is the 29th snowiest ski area on earth and gets rain on 30% of its winter days. Antillanca is 60th and gets rain on half of them. These are volcanoes in the Chilean lake district, close to the Pacific, and the same moisture that makes them extraordinarily snowy also arrives as rain when the temperature is a degree the wrong way.

Las Leñas is the exception that makes the trip planning easy. It is first in the southern hemisphere for snowfall and first for quality. Nowhere else on the list wins both.

What to do with this

If you are going south for powder, go high and go inland. The band from Portillo through Las Leñas to Penitentes — roughly 33°S, 2,600 m and up — is where the southern hemisphere’s dry snow is. Everything about it is harder to reach than Queenstown, and that is exactly why it is still good.

Read the rain column before the snowfall column in the lake districts and in New Zealand. A resort with 500 cm and rain on half its days is not offering you 500 cm of powder. It is offering a snowpack that repeatedly gets wet and refreezes.

Australia is a different proposition and should be planned as one. Its ten ski areas have a median quality score of 1.3 against Japan’s 8.5, driven by 38% rain days and snow falling at around −1 °C. That is not a reason not to go — it is close, it is a good time, and the alternative is a fifteen-hour flight. It is a reason not to expect what the photographs from Hokkaido show.

And if you are choosing between hemispheres on snow alone, Japan still wins. Forty-four Japanese ski areas beat the best in the south, and the top of the Japanese list is not close to being challenged. What Argentina offers is that it is July.

How this was measured

The quality score combines four things from the ERA5 reanalysis, measured identically at every ski area: how cold it is on days snow falls (the main component — colder snow is lighter), how often 5 cm or more falls, how many days see 1 mm or more of rain, and how hard the wind blows on snow days. They are multiplied rather than added, so a place that is cold but dry, or snowy but warm, cannot score well on one strength alone. Snowfall totals are deliberately excluded — that is what our snowfall ranking is for, and mixing the two would just reproduce it.

The thresholds and weightings are our judgement, not a result. What the score is good for is ordering places measured the same way. The absolute number means little.

Air temperature is corrected for elevation, and this matters more in the Andes than anywhere. A reanalysis grid cell flattens the mountains inside it, so the temperature it reports is not the temperature at the ski area. Las Leñas sits 320 m above its grid cell’s elevation, which moves its snow-day temperature from −1.1 °C to −3.2 °C using the standard 6.5 °C/km lapse rate. All 55 southern ski areas received this correction. It is a model, not a measurement, and a resort that is steeper or more sheltered than the correction assumes will be misplaced by it.

Three limits to state plainly. The pool is 88% Japanese — 395 Japanese ski areas against 55 southern ones — so a rank out of 450 describes position within that set and not within the world. We also record each ski area’s rank within its own country, which does not move when we measure another country; the Japanese ranks quoted in our earlier articles are those, and they are unchanged by this work. Daily totals are aggregated on Japanese calendar days for every ski area, which is the right boundary for Japan and shifts the day boundary by about half a day in the Andes; it affects which calendar day a snowfall lands on, not how much fell over a season. And three winters is a short record, particularly in Argentina, where the year-to-year swing is the widest we measure anywhere.