During a sandstorm, the evasion of the Pokémon with this Ability is increased by 25%. The Pokémon with this Ability will take no damage from the sandstorm if it otherwise would. It can be considered a sandstorm counterpart to Snow Cloak.
Outside of battle[]
If a Pokémon with Sand Veil is the leading the party while travelling in a sandstorm (even if fainted), wild Pokémon are 50% less likely to appear.