Overcoat

Overcoat makes the Pokémon immune to residual damage from weather conditions (specifically Hail and Sandstorm).

Game descriptions

Black, White, Black 2, White 2:Protects the Pokémon from damage from weather.
X, Y, O.Ruby, A.Sapphire:Protects the Pokémon from things like sand, hail, and powder.
Sun, Moon, Ultra Sun, Ultra Moon:Protects the Pokémon from things like sand, hail, and powder.
Sword, Shield, B.Diamond, S.Pearl:Protects the Pokémon from things like sand, hail, and powder.
Scarlet, Violet:The Pokémon takes no damage from sandstorms. It is also protected from the effects of powders and spores.