Regardless of the Pokémon game, Castform is always a bit of an outlier. Despite having no evolutions and being relatively weak, it has four unique forms and a gimmick that makes catching them all a bit difficult—especially in Pokémon Go.
Known as the Weather Pokémon, Castform has a regular form that can shift in three different states depending on what is happening in the atmosphere around it. Each form has a different typing and a unique design that plays into the weather condition it represents, and unlike in a regular Pokémon game, your Castform will stay in the form you catch it in rather than only changing in the right weather.
The weather change doesn’t really help you use Castform in actual battles, but it does make catching all four forms more entertaining if you know what to look for in Pokémon Go.
Castform Pokémon Go catch and weather guide: How to get all forms
Castform has four different forms in Pokémon Go–Normal, Sunny, Rainy, and Snowy. These four forms have been the same since the Weather Pokémon was first introduced in Pokémon Ruby and Sapphire alongside the first weather mechanics for the franchise.
Since Pokémon Go’s in-game weather changes based on your real-world location and weather data, you can’t manipulate it like you can in a regular Pokémon game. And, because Castform will only appear in its various forms in the right weather conditions, this can make it a bit tough to get all four.
Here is a guide for when each Castform form will appear in Pokémon Go depending on the weather you see in your game’s overworld—accounting for each of the main weather conditions in the mobile game.
| Castform Form | Model | Weather Conditions for Spawn |
| Castform Normal |  | Partly-cloudy, Cloudy (overcast), or Windy weather spawn. |
| Castform Sunny |  | Sunny/Clear weather spawn. |
| Castform Rainy |  | Rainy weather spawn. |
| Castform Snowy |  | Snowy or Foggy weather spawn. |
If you want to get every Castform form easily, you can occasionally find it as a featured spawn or guaranteed encounter during events like Weather Week 2024 where you also might be able to catch a Shiny.
