Artificial snow is ice or ice-like material produced by machines rather than by natural weather. It comes in two very different forms: the frozen water sprayed onto ski slopes by snow guns, and the polymer-based flakes used for movie sets, window displays, and holiday decorations. Both mimic the look of real snow, but they’re made from completely different materials and work in completely different ways.
How Snow Guns Make Snow at Ski Resorts
Ski resort snowmaking forces pressurized water through small nozzles while simultaneously blasting compressed air into the atmosphere. The compressed air, typically at 70 to 120 psi, cools rapidly as it expands after leaving the snow gun. When mixed with a small amount of water, this expansion creates tiny ice crystals called “seed” nuclei. These seeds then attract and freeze the larger water droplets sprayed by the gun’s water pump, and the frozen droplets fall to the ground as snow.
The ratio of air to water is surprisingly high. Many commercial snow guns use over 200 cubic feet per minute of compressed air while spraying less than 20 gallons per minute of water. That’s an air-to-water ratio that can reach 40:1, especially when temperatures are only marginally cold enough for snowmaking. The colder the air, the less compressed air is needed to freeze each water droplet, so resorts can produce snow faster and more efficiently on truly cold nights.
Temperature and Humidity Limits
Snowmakers don’t rely on the number you see on your weather app. They use something called wet bulb temperature, which factors in both air temperature and humidity. Dry air helps water droplets evaporate slightly as they fly through the air, and that evaporation pulls heat away from each droplet, helping it freeze. So on a dry day with only 5% humidity, snow guns can operate at air temperatures as warm as 30°F. On a humid day, the machines may need it much colder.
Most resorts start looking at snowmaking around 26°F wet bulb, but efficiency at that temperature is poor. The sweet spot is 15°F wet bulb, where machines run efficiently and snow piles build quickly. Above 26°F wet bulb, resorts generally have to shut down entirely. More advanced gun models from manufacturers like TechnoAlpin can push a few degrees warmer, operating up to about 25°F wet bulb, while simpler snowmaking sticks need it well below 15°F to work at all.
Biological Additives That Help Ice Form
Some ski resorts add a product called Snomax to their water supply. It contains proteins derived from a common bacterium, Pseudomonas syringae, that exists naturally on plant surfaces. These proteins act as ice nucleation agents, meaning they give water molecules a structure to latch onto and start forming ice crystals at warmer temperatures, up to about 28°F instead of needing significantly colder air. The bacteria themselves are not alive in the final product. The proteins simply make the freezing process more efficient, letting resorts produce more snow with less energy when conditions are marginal.
How Machine-Made Snow Differs From Natural Snow
Natural snowflakes form slowly in clouds, building outward into the iconic six-armed crystal shapes as water vapor deposits onto a tiny particle. This process takes minutes and produces intricate, flat structures full of air pockets. Snow guns, by contrast, freeze water droplets in seconds as they arc through the air. The result is tiny, dense ice beads about one ten-thousandth of an inch in diameter, closer to spheres than to the branching patterns of natural flakes.
This shape difference has practical consequences. Because ice beads are round and compact, machine-made snow packs more densely on the ground. It feels harder and icier underfoot than a fresh natural snowfall. The contact surface between beads is also different from the way natural flakes interlock, which changes how quickly the snow melts under pressure from skis, boots, or warm air. Machine-made snow generally lasts longer on slopes because its density makes it more resistant to melting and wind erosion, which is precisely why resorts invest millions in snowmaking infrastructure.
Decorative and Theatrical Snow
The “snow” you see in movies, store windows, and holiday displays is an entirely different material. It’s typically made from sodium polyacrylate, a superabsorbent polymer sold as dry granules or flakes. When you add water, the polymer chains absorb up to 800 times their own weight, swelling into a soft, white gel that looks remarkably like fresh powder. The granules are shredded to a size and color that mimics real snowflakes, and they’re often blown around with fans to simulate a snowfall effect on stage or on film sets.
Sodium polyacrylate is considered non-toxic and safe for general decorative use. However, safety data sheets note that the dry powder can cause mild eye irritation on contact, and the wet product creates slippery surfaces. For large-scale theatrical productions where the material might become airborne as fine dust, proper ventilation is recommended. If it gets in your eyes, flushing with cold water is the standard response. It’s not a significant ingestion hazard in small amounts, though it’s obviously not meant to be eaten.
You can buy instant snow powder online or at hobby stores for a few dollars. A tablespoon of dry granules mixed with water produces roughly a cup of fluffy fake snow that holds its shape for days before slowly drying out.
A Brief History of Snowmaking
The technology dates back to 1950, when three Americans, Art Hunt, Dave Richey, and Wayne Pierce, invented the first snow cannon. Two years later, Grossinger’s Catskill Resort Hotel in New York became the first venue in the world to use artificial snow commercially. The technology spread quickly through the ski industry during the following decades, and today the majority of ski resorts in the eastern United States and much of Europe rely heavily on snowmaking to guarantee a consistent season regardless of natural snowfall.