Perfecting the slopes for the 2026 Winter Olympics

Cast your mind back, to the second week of January 2026. Across the slopes of Cortina d'Ampezzo and Bormio, a white blanket covers the mountains. The local New Year’s celebrations have finished, and 1.6 million cubic metres of machine-made snow is ready for the upcoming Winter Olympics. The only signs that the snow is machine-made are the bright yellow snow guns that appear like a connect-the-dots puzzle alongside the ski slope.

Snow is critical to the Winter Olympics, but climate change is making conditions less favourable. Alpine landscapes that historically accumulated one to two metres of natural snowfall each season are now increasingly rare. In 2023, the former International Olympic Committee President, Thomas Bach, noted that it’s likely that only 10 to 12 countries will be able to host the Winter Olympics by 2050.

Warming winters and a push for a more sustainable infrastructure mean hosts such as Italy must now find solutions to this challenge. Working in the background, engineers from around the world have come up with ways to ensure consistent amounts of snow are available during the games, while athletes adapt their performance and training to the conditions of the engineered snow.

The ideal ski racing slope

Like a high-budget film set, Winter Olympic ski slopes are highly constructed environments, shaped through land-forming, grooming, and snowmaking.

Slope design is important to ensure that competitions run smoothly. Competition courses require dense, compacted, strong snow that won’t break up when over 100 skiers launch themselves down the slope, to ensure consistency throughout the competition.

“It's always good to have quite a hard slope,” says Nemanja Dogo, who has worked at TechnoAlpin, the maker of the snow guns for the Milan and Beijing Winter Olympics Games, since 2018. “If the slope is harder, then the conditions for the first athlete and the 150th are more or less than same.”

The secret to a hardened slope is a process called watering, where (unsurprisingly) water is sprayed or injected into the top layer of snow. Rather than forming a dangerous icy crust, the idea is for it to percolate into the snow, mixing, bonding and freezing into a resistant layer.

Of course, before slope managers can get to that resistant layer, they first need a foundation of snow. 

How to make snow

When natural snow falls short, snow fan guns and their smaller equivalents, snow lances, come to the rescue. Fan guns are well-suited for wide slopes that require a lot more snow over a large area. Lances, on the other hand, are better for narrow cross-country trails that require more accuracy where the snow lands.

Machine-made snow requires water, from a reservoir or a natural source, to be cooled and pumped into the gun. For the Milan-Cortina Olympics, organisers constructed a lake in Bormio, the site of the men’s ski races, to hold 88 million litres of water for snowmaking. For the Livigno freestyle and snowboarding events, they built a 200-million-litre basin, and two machine rooms that can pump up to 369 litres of water per second to the system of snow guns  via underground pipelines.

To bring it to the right temperature for snowmaking, the water travels via cooling towers before being pumped into the fan guns. Tiny ice crystals or snow nuclei, known as nuclides, are produced when the water is injected into compressed air and expands from the pressure difference.

At the same time, water nozzles produce a mist of finely atomised water droplets. The mist and nuclides are blown into the air by a fan, and as the water droplets attach to the nuclides in the air, they form ‘ice beads’, rather than snowflakes. As they subsequently fall onto the ground, they pack neatly like small spherical balls with small pore spaces in between them. This uniform structure makes its mechanical properties less variable than natural snow.  

Snowmakers can finely tune the properties of machine-made snow. “You can change the snow quality from one to nine,” says Dogo. A higher number indicates wetter snow, although he points out that external temperature and humidity are important constraints.

To improve their efficiency, snow guns are usually run at night, when temperatures are cooler. Luckily for the organisers of the Milan-Cortina Olympics, a cold spell throughout Europe after Christmas enabled them to run the systems during the day too, says Dogo.

But conditions are not always this ideal. At temperatures above -8°C or in relatively high humidity, snowmakers can introduce nucleating agents (see ‘Natural vs machine-made’), such as aluminosilicate minerals, known as feldspar, or sometimes bacteria. These nucleating agents help snow guns become more efficient – using less water and energy to produce snow.

Maintaining slopes during the Olympic Games

After an eventful day of competitive skiing, mountains, like athletes, need rest and repair. The slope management team of the Olympics sets to work every night after the slopes close. Their job is to repair slope damage, redistribute snow, and regenerate a trail’s surface – a process known as ‘grooming.’

 The ideal conditions to groom the slope is when the snow is highly deformable – slightly wet and pushed to the bottom of the slope – and the temperature is close to zero. This is usually shortly after a slope closes, when the snow is still warm and easy to process. There is also enough time for the snow to consolidate, known as the respite period.

The snow groomers used in the Olympics are more advanced than those put to work on commercial ski slopes. Advanced GPS systems and software on the Olympic-grade machinery can determine how much snow is needed and where to put it. These tracked vehicles usually have a tiller to break up the snow and a blade to cut and shape the snow, so they can collect snow, redistribute it, and smooth surfaces.

Advances in snowmaking

As global snowfall continues to decline, researchers have been developing ways to make and store snow in more efficient ways, to ensure leisure skiing can continue and competitions can go ahead. In countries with cooler climates, such as Norway, snow storage has been an effective strategy for preserving snow. Snow is conserved in insulating materials, such as sawdust, between April and the end of September.

Meanwhile, at Spain’s oldest ski resort, La Molina, Dr Albert Verdaguer and researchers from the Institut de Ciencia de Materials de Barcelona are testing whether feldspar will boost ice crystal nucleation when temperatures are on the warmer side. So far, the group’s research indicates this approach could enable snow production at temperatures 1 to 1.5°C higher than traditional approaches, and reduce energy costs by 30%.

At the Olympics, advanced weather forecasting software integrated into snowmaking tools will prevent overproduction of snow. For a system that has over 1,000 snow guns, the efficiency and accuracy of snowmaking is vital, as changing weather conditions during snowmaking can change where the snow falls. “We can predict which side the wind is coming, so we can change the position of the snow guns,” Dogo explains, “[to ensure] the snow falls on the trails.” And when needed, the machines can also stop snow production to prevent wasting water and energy.  “It’s important to switch off the whole system immediately in warm temperatures to prevent spreading water.”

However, advances in snow gun and snow grooming software and technology notwithstanding, the snowmaker has the final say on how to achieve the optimal quality of snow on the slope. “Every snowmaker has their own idea … on how they want to make the snow,” says Dogo. In the eyes of a snowmaker, preparing an Olympic slope is a combination of engineering, science, and art.

For athletes, the conditions of the slope require adaptivity. Caryn Davies, a former US Olympic and Paralympic alumni president, a three-time gold medallist in rowing and former competitive skier, explains the need to respond to different snow conditions. “You have to adjust your equipment: different types of snow require different wax. You also have to adjust your technique, since your skis will respond differently to pressure if the snow is soft or hard, powdery or granular.” 

As an elite athlete, Davies says, “I always looked at the conditions with equanimity: variable conditions are part of the sport. It's all how you handle it.”