Snow Cloak is an ability introduced in Generation IV. It raises Evasiveness when it is hailing. It also makes it less probable that you will come across wild Pokémon when it is hailing. If a non--Type Pokémon possesses this ability, it will not be hurt when it is hailing.
Effect in Battle
Snow Cloak raises the user's evasion in a hailstorm.
Effect Outside out Battle
If a Pokémon with the ability Snow Cloak is placed first in the party in hailing weather, the chances of running into wild Pokémon decreases by 50%.