Choosing right wax

Wax should be chosen depending on temperature

The thing that needs to be remembered is that wax should be chosen according to the outside conditions. It can be as complicated as considering all factors, like humidity, temperature, wind, sun, reflectivity and age of snow. It can also be as simple as taking in consideration only the temperature. Let's go over two the most important factors.

Temperature

The basic rule to remember is that harder wax should be used for colder days and softer wax for warmer ones.

There is no optimal wax that will work for the whole temperature range. That means if you apply wax that is too hard for the weather, there will be little friction and you'll find that moving is hard, just like walking on the icy lake. Likewise, if you use the wax that is too soft for the temperature, ice crystals will deeply penetrate into the wax, friction will be very large and snow will quickly stick to the bottom of the skis making it hard to move. These cases are clearly shown in the Figure 1.

Figure 1. Picture from Sports Illustrated: Cross-Country Skiing

So check temperature before you leave to ski and make sure that you take some wax with you in case temperature would change.

Shape of snow crystals

Even though temperature matters the most, age of the snow may also affect the performance of the skis.

New snow crystals are usually shaped like stars and have sharp edges. When skiing on the new snow, one should use hard wax. Otherwise snow crystals would penetrate wax too deep with their sharp edges and friction will be greater. When skiing on packed or wet snow, crystals shaped more like little balls, so softer wax can be applied.

Figure 2. Picture from Cross Country Skiing by Sindre Bergan

Whatever snow conditions are, according to Sport Illustrated author Casey Sheahan, "the colder the air temperature, the harder wax you'll apply to the midsection of your skis." There are wide range of waxes available, however Blue(warmer, most used) and Green(colder) waxes are best for Fairbanks according to the Beaver Sports.