You Book Six Months Ahead. Italy's Snow Swings Twice as Wide as Japan's.

Nobody books a ski week for the average winter. You book one week, in one place, half a year before anyone knows what the weather will do — and then you get whatever that winter turns out to be.

So the useful question is not how much snow a place gets. It is how far the answer moves.

The spread, by country

For every ski area we hold three winters of snowfall. Divide the best by the worst and you get how wide the swing was.

	Ski areas	Best winter ÷ worst
Japan	395	1.45
Sweden	69	1.45
Germany	77	1.45
France	250	1.48
Canada	172	1.48
Spain	35	1.52
New Zealand	25	1.55
Switzerland	287	1.58
United States	541	1.58
China	180	1.64
Austria	248	1.73
Norway	137	1.77
Italy	188	2.07

Across all 3,105 the middle value is 1.63.

A typical Italian ski area’s good winter is more than double its bad one. A typical Japanese one is up by less than half. Those are different propositions for someone committing to dates in August.

The two facts stack, too. Japan is both the snowiest country in this table and the steadiest — it gets 268 cm in the middle case and does not stray far from it. Italy gets 201 cm in the middle case and can hand you anything from 131 to 301.

What a wide swing looks like in one place

Among ski areas substantial enough to plan a trip around — over 200 cm a season and over 20 km of piste — these had the widest spread across the three winters:

Ski area		Worst → best winter	Swing
Cambre d’Aze	🇫🇷	113 → 356 cm	3.15×
Valmalenco Bernina	🇮🇹	143 → 399 cm	2.79×
Hoodoo	🇺🇸	213 → 574 cm	2.69×
Bormio	🇮🇹	116 → 312 cm	2.69×
Passo Stelvio	🇮🇹	114 → 301 cm	2.64×
Kaunertaler Gletscher	🇦🇹	124 → 327 cm	2.64×

Four of the six are in the Alps’ southern rim, where a winter depends on how often low-pressure systems track across the Mediterranean rather than north of the range. When they do, it is a huge year. When they do not, there is very little.

And the other end — places where all three winters landed almost on top of each other:

Ski area		Worst → best winter	Swing
White Pass	🇺🇸	518 → 529 cm	1.02×
Le Grand Domaine	🇫🇷	348 → 366 cm	1.05×
Leysin	🇨🇭	257 → 273 cm	1.06×
Crystal Mountain	🇺🇸	528 → 565 cm	1.07×
Kamui Ski Links	🇯🇵	203 → 221 cm	1.09×

White Pass in Washington had 518, and then 529. That is as close to a guarantee as this dataset contains.

Three winters is not many, and it matters here

Be careful with the individual resorts above. A ratio built from three numbers moves a long way on one unusual year — a single thin winter is enough to put a place on the first list, and it may not belong there. Treat those rows as illustrations of what a wide swing looks like, not as a verdict on those mountains.

The country figures are a different matter. Italy’s 2.07 is the middle of 188 ski areas and Japan’s 1.45 is the middle of 395, so one odd winter at one resort cannot move them. The country-level pattern is the finding here. The named resorts are just the pattern made visible.

How to use it

If your dates are fixed and cannot move, weight reliability over headline snowfall. A place that reliably gets 250 cm is a better bet for one specific week than a place that averages 300 cm by alternating between 180 and 420.

If you can move your dates, the opposite holds. Variance is only a risk when you are locked in. If you can book late and go where it has snowed, a high-variance region is where the exceptional weeks come from.

And check the spread on the resort you are looking at, not just its country. Every ski area page on this site carries a “range over three winters” row with its own two numbers. The country median tells you the habit of a region; that row tells you about the mountain you are actually considering.

How this was measured

Snowfall is the three-winter mean from the ERA5 reanalysis, computed the same way for all 3,105 ski areas, with the hemispheres offset so a southern winter is measured in its own season. The model understates mountain snowfall everywhere; that matters for the centimetre figures and not for the ratios, because a consistent understatement divides out.

Three winters is the whole record we hold, which is enough to compare countries with hundreds of ski areas each and not enough to characterise a single mountain. A longer record would narrow the extremes on both lists above — the steadiest would look less steady, and the wildest less wild.

Ski areas with a worst winter of zero are excluded, since dividing by zero produces no ratio. Countries with fewer than twenty ski areas are left out of the country table, and the named lists are limited to ski areas with over 200 cm a season and over 20 km of mapped piste, so that they are places somebody would actually plan a week around.