Snowmaking is the production of snow by forcing water and pressurized air through a “snow gun,” also known as a “snow cannon.” Snowmaking is mainly used at ski resorts to supplement natural snow. This allows ski resorts to improve the reliability of their snow cover and to extend their ski seasons from late autumn to early spring. Indoor ski slopes often use snowmaking. They can generally do so year-round as they have a climate-controlled environment.

The use of snowmaking machines is becoming increasingly common as changing weather patterns and the rising popularity of indoor ski resorts create a demand for snow beyond that which is provided by nature. Snowmaking machines have addressed the shortage in the supply of snow, however, there are significant environmental and cultural costs associated with the artificial production of snow.

According to the European Environment Agency, the length of snow seasons in the northern hemisphere has decreased by five days each decade since the 1970s, thus increasing the demand for the production of artificial snow. Some ski resorts use artificial snow to extend their ski seasons and augment natural snowfall, however, there are some resorts that rely almost entirely upon artificial snow production. Furthermore, artificial snow was used extensively at the 2014 Winter Olympics in Sochi, and the 2018 Winter Olympics in Pyeongchang to supplement natural snowfall, and provide the best possible conditions for competition.

The production of snow requires low temperatures. The threshold temperature for snowmaking increases as humidity decreases. Wet-bulb temperature is used as a metric since it takes air temperature and relative humidity into account. Snowmaking is a relatively expensive process in its energy use, thereby limiting its use.

By the 2009-2010 ski season, it is estimated that around 88% of ski resorts belonging to the National Ski Areas Association were using artificial snow to supplement natural snowfall.

Since 1985, average aggregate temperatures in the Contiguous United States for the months of November through February have consistently been above the average temperatures for those months measured between 1901 and 2000.[14] See Figure 1. Such a trend both limits and encourages the use of artificial snow. Rising temperatures will result in greater snowmelt and decreased snowfall, thus forcing ski resorts to depend more heavily upon the use of artificial snow. However, once temperatures approach 43 °F, snowmaking is not viable given the current technology. The image to the right, Photo 1, demonstrates the use of artificial snow to supplement natural snowfall. The strip of white going down the mountain is a ski slope that has been opened due to extensive use of snowmaking technology.
As the use of artificial snow becomes more common and efficient, developers may seek to build new or expand existing ski resorts, as was the case with the Arizona Snowbowl ski resort. Such an action could cause significant deforestation, the loss of fragile and rare ecosystems, and cultural opposition. The high costs associated with the production of artificial snow serve as a barrier to entry for its use. It was estimated that in 2008 it cost approximately US$131,000 to purchase a snow gun and develop the necessary infrastructure. Overall, approximately US$61 million have been invested in snowmaking technology in the French Alps, the US $1,005 in Austria, and the US $415 in Switzerland.[15] Furthermore, 50% of the average American ski resort’s energy costs are generated by the production of artificial snow.