Where can you find Castform in Sun & Moon?

Question

Your "Where to find Castform" section says "Trade or migrate from another game", but Castform must be encounterable in Sun or Moon since it's in the Alola Pokédex, so where can I encounter it?

Answer 1

You can only encounter Castform via S.O.S. Chaining, while a weather condition is active. Some of the places where weather is (usually) constant are Malie Garden, Haina Desert, & Mount Lanakila. I think it has a low encounter rate, so you might just wanna try the GTS first.

Answer 2

Castform is found in multiple places, but only via SOS chaining. It also needs to be either raining or snowing too.

Rain
Lush Jungle - South
Lush Jungle - West
Lush Jungle - North
Route 17
Exeggutor Island
Haina Desert
Mount Lanakila - Mountainside
Mount Lanakila - Mid-Point
Tapu Village

Snow
Malie Garden

Source

Comments

I dont think it matters whether the weather will be a specific condition of weather that you'd need to weather through, but rather whether there IS weather to weather through to get to the weather Pokemon... At least, according to Bulbapedia: http://bulbapedia.bulbagarden.net/wiki/SOS_Battle#Weather-dependent_allies