1 species has Dry Skin as a hidden ability, 6 as a normal one

Effect, in PokéAPI's words

“Causes 1/8 max HP in damage each turn during strong sunlight, but heals for 1/8 max HP during rain. Increases damage from Fire moves to 1.25×, but absorbs Water moves, healing for 1/4 max HP.”

As a hidden ability

Species	Slot	Note
Jynx	Hidden	Since Generation V

As a normal ability

Species	Slot	Note
Paras	Normal	Since Generation IV
Parasect	Normal	Since Generation IV
Croagunk	Normal
Toxicroak	Normal
Helioptile	Normal
Heliolisk	Normal