When is a ski resort actually allowed to make snow? The rules in Switzerland and Austria

There is a claim you hear again and again in ski resorts: snowmaking is only allowed once natural snow is already lying. It sounds sensible, it sounds Swiss, and it is not true in that form.

The sentence does exist, almost word for word. It simply does not appear in any Swiss law but in an Austrian position paper, and it is not a prohibition but a condition attached to an exception. What actually applies is more complicated, and in places the exact reverse of the common assumption.

First: Switzerland has no snowmaking act

There is no federal law on technical snowmaking. What exists are four pieces of federal legislation reaching in from different directions:

Everything beyond that is cantonal, and the cantons do it differently. That is the heart of the matter: in Switzerland, the answer to “from when may snow be made” depends on which canton the lift stands in.

Canton of Bern: the hard calendar

Bern regulates it in its building ordinance, tersely and unmistakably. Article 29d, a single sentence:

Snowmaking is permitted from 15 October up to and including 15 March.

No discretion, no weather condition, no exemption procedure in the text of the ordinance. A Bernese resort may not make snow on 14 October, even at minus ten degrees, and not on 16 March, even with Easter still ahead.

The three articles before it are just as concrete:

• From 5000 m² of snowmaking area, a basis in the municipal land-use plan is required. That is half a hectare, a very low threshold.
• Visually conspicuous snowmaking equipment must be dismantled in summer. A pure landscape provision, and the reason why fewer snow guns stand around in Bernese resorts in July than elsewhere.
• Water abstraction follows a priority order: first public water supply or hydropower installations, then existing intakes, then new groundwater intakes and high-capacity watercourses, and only as a last resort uncaptured springs.
• And the sharpest sentence: “Only water may be used for technical snowmaking. Any additions of substances or organisms are prohibited.”

Remember that last point. It comes back shortly.

Grisons: calendar abolished

Switzerland’s largest ski canton does it differently, and it changed it deliberately. Until 2007, Grisons also had fixed dates. The revised guidance from the Office for Spatial Development deleted them. The introduction lists it explicitly as a change: “no fixed earliest snowmaking date”.

A condition took the place of a date:

Snowmaking may only take place when temperatures are suitable for producing snow. The ground should, except for snowmaking to build snow depots, be frozen where possible, in order to prevent soil erosion.

That is the core of it, and it contains half the truth of the claim quoted at the start. Not “when snow is lying” but “when the ground is frozen”. Nor is the purpose cosmetic; it is erosion control. On unfrozen ground, the weight of the snow cover and the meltwater tear up the turf.

And even this rule is softly worded, “where possible”, with an explicit exception for snow depots. Anyone producing snow in spring for a depot is exempt. What comes of that is described in our article on snowfarming.

On top come conditions with real teeth:

• Storage reservoirs rather than stream intakes, and abstraction from surface waters during the winter months should be avoided as far as possible.
• Mires and dry meadows of national importance may effectively not be covered with machine-made snow.
• No environmentally hazardous substances may be added to the snowmaking water.
• From 15 to 20 hectares the canton recommends land-use planning with a municipal vote, and from 10 hectares in ecologically sensitive cases.

One detail shows how serious the canton was about the loosening: where older permits still contained dates, the guidance declares them void.

The additive that divides the countries

Now to the point where most people guess wrong.

There is a product called Snomax, made from killed bacteria. The proteins it contains act as crystallisation nuclei and raise the nucleation temperature by four to five degrees. In plain terms: with Snomax the system runs at temperatures at which it would otherwise stand idle, and efficiency rises by 10 to 30 per cent.

Who would permit it, who would ban it?

So the country with the reputation for strict environmental protection permits the substance at federal level, and Tyrol of all places, known for maximal snowmaking, bans it.

The Tyrolean episode behind this is instructive. In the summer of 2018 the regional administrative court allowed the cableway company in Seefeld to use Snomax. Independent samples had previously found not only bacterial residue but living bacteria and enterococci. A political storm followed, and in the same year the regional parliament passed a ban on additives together with a drinking-water-quality requirement. The court had been upheld, and then the law was changed.

Tyrol: not dates but an altitude ladder

Anyone wanting to make snow in Austria needs a water rights permit, and that permit specifies volume and period. The periods are therefore installation-specific, not uniform across the region.

Speaking into those proceedings is the Tyrolean environmental ombudsman office, an independent authority. Its position paper on bringing snowmaking dates forward is the document the claim quoted at the start comes from. It states that a start before 1 November is “extremely critical”, then lists six conditions under which earlier snowmaking might be considered:

1. Air temperature is below freezing.
2. The ground is frozen through at least at the surface.
3. The surrounding landscape already has a wintry character from natural snowfall.
4. The licensed water volume is not increased.
5. The weather forecast shows no warm spell.
6. The altitude ladder is observed.

Point 3 is the sentence in question. It is not a general snowmaking rule but one of six conditions for being allowed to start earlier than usual. And it is justified not on ecological grounds but on landscape grounds: “white ribbons of snow in the middle of a snow-free landscape” are intrusive.

The altitude ladder from point 6:

A comparison that captures the systems: a resort at 1900 metres may, under this recommendation, start on 1 October in Tyrol. In the canton of Bern the same resort at the same altitude may start on 15 October at the earliest and must stop on 15 March. In Grisons, conversely, it may make snow as soon as it is cold enough, with no date at all.

One more thing appears in the Tyrolean paper that is rarely read: in October, wildlife is preparing for winter, and noise, light and activity around the guns push animals out of the last remaining feeding grounds. Snowmaking installations reach 60 decibels and more in operation.

South Tyrol: a concession and zero additives

South Tyrol regulates it via the water concession. Additives are prohibited, all water used is tested for suitability, and operators must run their own monitoring. Storage reservoirs are mandatory so that water is used rationally.

South Tyrol also supplies a figure we can put to good use, because it confirms a calculation of our own: around 3000 hectares there can be covered with machine-made snow, that is 70 to 80 per cent of the pistes, and in the 2018/19 season roughly 11 million cubic metres of water went into it. That works out at a good 3600 m³ per hectare, and it falls exactly within the range of 3000 to 4500 m³ we derived from physics in our article on water and power consumption. Two independent routes, the same result.

And Ischgl? A common mix-up

Ischgl regularly runs until early May, in the 2025/26 season until 3 May. This is often taken to mean that snowmaking there is unusually deep and unusually massive.

That is a mix-up. Ischgl’s village sits at 1377 metres and the ski area reaches 2872 metres, with north-facing slopes on top of that. The long season comes from altitude, not from the snow gun.

The resort that represents the opposite case is Kitzbühel: base station at 800 metres, 570 metres lower than Ischgl, and still a dependable ski operation. There, everything technology has to offer really does come together:

• over 1260 snow generators
• 40 storage ponds holding around 2.5 million cubic metres of water in total
• snowfarming with around 24,000 m³ of stored snow
• and, as the first non-glacier resort, a snow guarantee, in the 2025/26 season from 21 December to 14 March

So anyone wanting to know how far a low-lying ski area can be carried by technology should look not at Ischgl but at Kitzbühel. And will see there what it costs.

What this means in practice

Four points to take away.

1. There is no Swiss rule, there are cantonal rules. Bern has a fixed calendar, Grisons no longer has one. Anyone speaking of “the Swiss regulation” usually means their own canton.
2. The widespread claim is a conflation. Switzerland has the condition “ground frozen where possible”, not “snow must be lying”. The sentence about the wintry character of the landscape comes from Tyrol and applies there only to the special case of early snowmaking.
3. On the additive, Switzerland is the more permissive side. Snomax is approved at federal level, while Tyrol, South Tyrol, Bavaria and the canton of Bern all ban it.
4. The hardest limit is not a legal one. Without a wet-bulb temperature of about minus three degrees, no gun runs, whatever the permit says. No canton and no parliament can change that.

As of 10 August 2026. Legal texts change; for any specific case the current enactment of the canton or region concerned applies, not this article.

Sources: Building Ordinance of the Canton of Bern (BSG 721.1), Art. 29a to 29d, as of 1 May 2024; Office for Spatial Development of the Canton of Grisons, guidance on snowmaking installations 2007 in the version of 1 September 2008; Ordinance on Environmental Impact Assessment, installation type 60.4; position paper of the Tyrolean environmental ombudsman office on bringing snowmaking dates forward; Autonomous Province of Bolzano on technical snowmaking; Austrian Alpine Club on snowmaking (noise levels, share of pistes covered, Tyrolean additive ban 2018); Tiroler Tageszeitung on the course of the Snomax case; Iseli, Künstliche Beschneiung in der Schweiz, University of Bern 2015 (effect and approval of Snomax); figures on Kitzbühel and Ischgl per the cableway companies and regional portals.