Pokemon GO will introduce a new shiny Castform next week when the Weather Week event debuts. While the shiny Normal-type Castform has appeared before, the Rainy Form Castform will be the first of the weather types to receive a shiny form to catch in Pokemon.
Weather Week will sweep Pokemon GO up in its rough weather next week as the Charge Up! event comes to a close. Therian Forme Thundurus brought storms for the Electric-type event, and the after-effects are what Weather Week will be based around.
Pokemon that enjoy rough weather such as rain and wind, like the shiny Castform, will be taking over in the wild.
Therian Forme Tornadus will take over for Therian Forme Thundurus as the new event starts, but it's not the only debut happening during Weather Week in Pokemon GO. Shiny Castform will appear for the first time as the rainy form.
As with almost any shiny Pokemon in Pokemon GO, there won't be a guaranteed way to catch a shiny Castform during the event. It will always come down to luck, but there are some methods to increase the chances of getting one, especially if players know how the event works.
Shiny Castform could appear in the wild like anything else, and players can maximize their encounters with the rainy form Castform. Using incense and walking around populated Pokestops will increase the chances of a shiny Castform by the amount of encounters alone.
When certain Pokemon like shiny Castform are featured in an event for Pokemon GO, they typically appear in raids and 5km eggs. Based on the information given, shiny Castform won't appear in eggs, but one-star raids are still possible.
Field research tasks and timed event tasks are confirmed to have a chance for shiny Castform if all else fails.
Weather Week and shiny Castform in Pokemon GO
Weather Week in Pokemon GO isn't just about getting the shiny Castform as a rainy form. Therian Forme Tornadus is one of the main draws and is also the cause of the windy conditions in-game.
The event's basis is to catch Pokemon that are acclimated to rough conditions such as rain and wind. There will be three-day rotations of Pokemon that are Flying-type based and Pokemon that are Water-type based.
Raids and 5km eggs will also reflect the event's theme, so players should stay on the lookout for event-themed Pokemon as things kick off on March 24th at 10 am local time.