#0351 · Hoenn · Generation 3

Castform

Weather Pokémon · Normal-type

Castform is a Normal-type Pokémon, the Weather Pokémon, number 351 (#0351) in the National Pokédex. It was introduced in Generation 3 and comes from the Hoenn region. It is 0.3 m tall and weighs 0.8 kg.

Castform is the Weather Pokémon, a tiny cloud that changes shape and type with the weather: Fire in sunshine, Water in rain and Ice in snow. The Pokédex says this is a chemical reaction of its cells and not a choice it makes.

How to pronounce Castform

Castform is pronounced KAST-form. The capital letters show the stressed syllable.

Listen to Castform said out loud:

In Japanese it is ポワルン (Powalen).

Hear every other name on the Pokémon pronunciation guide.

Lore

Biology

In its Normal Form Castform is a plain grey cloud, 0.3 m tall and 0.8 kg, with a large round head, a lighter mask-like marking over its eyes and a single wisp on top. The Pokédex says it takes the guise of the sun, rain clouds or snow clouds, and that its cells react to temperature and humidity.

Behaviour

Castform's mood follows the weather: the Pokédex says the rougher the conditions, the rougher its disposition. The Pokédex adds that it draws on nature's power to shield its small body. Bulbapedia says experiments to change its form under artificial conditions have all failed.

Habitat

The Pokédex lists a grassland habitat.

Powers

Its only Ability is Forecast, which changes its type and form with the weather: Sunny Form is Fire, Rainy Form is Water and Snowy Form is Ice. Weather Ball was its signature move in Generation III, and it also learns Rain Dance, Sunny Day, Hail, Hydro Pump, Fire Blast and Blizzard. Every one of its base stats is 70, so it is a balanced Pokémon whose strength depends on the sky.

Name origin

Castform may combine 'forecast' with 'transform' or 'form'. The Japanese name is Powalen (ポワルン), which may blend powan, the sound of a sudden transformation like 'poof', with kawaru, 'to change'.

Design inspiration

Castform resembles a living cloud, and Bulbapedia says a weather balloon may also have inspired it. Its concept is similar to the teru teru bozu, a Japanese charm doll hung to wish for good weather. The forms may come from the saying 'rain, hail or shine'. These are fan readings.

In the games

The Weather Institute hands you just one Castform in Ruby and Sapphire, the games where it first appeared. Bulbapedia lists it as unobtainable in Scarlet and Violet and in Legends: Z-A.

In the anime

Castform debuted in 'Unfair Weather Friends', owned by Bart, and changed into every one of its forms during the episode. In 'Currying Favor and Flavor!', Ash faced a Totem Lurantis and its Ally Castform in the Lush Jungle trial, and the Castform showed its Sunny Form.

Fun facts

• Bulbapedia says Castform is the only Normal type in the Amorphous Egg Group.
• Before Generation VII, Pokédex colour sorting classed its Normal Form as white.
• In Explorers of Time, Darkness and Sky it has a body size of 4, because all four forms' sprites are loaded into memory at once.
• At 0.3 m, Sunny Form Castform is tied with Heat Rotom, Litwick and Scorbunny as the shortest Fire Pokémon.

Sources: Bulbapedia: Castform (Pokémon) · Serebii: Castform (Sword/Shield Pokédex layout; lists Brilliant Diamond locations, as Castform is not in Sword and Shield)

Base stats

• HP: 70
• Attack: 70
• Defense: 70
• Sp. Atk: 70
• Sp. Def: 70
• Speed: 70

Castform’s base stat total is 420. Its highest stat is HP and Attack and Defense and Sp. Atk and Sp. Def and Speed.

Type matchups

What is Castform weak to?

Castform takes extra damage from Fighting (2×) moves.

It is immune to Ghost moves.

Evolution

Castform does not evolve, and it does not evolve from any other Pokémon.

Forms

• Sunny Castform (Battle form): Fire-type, base stat total 420 (HP 70, Attack 70, Defense 70, Sp. Atk 70, Sp. Def 70, Speed 70). Ability: Forecast.
• Rainy Castform (Battle form): Water-type, base stat total 420 (HP 70, Attack 70, Defense 70, Sp. Atk 70, Sp. Def 70, Speed 70). Ability: Forecast.
• Snowy Castform (Battle form): Ice-type, base stat total 420 (HP 70, Attack 70, Defense 70, Sp. Atk 70, Sp. Def 70, Speed 70). Ability: Forecast.

Abilities

• Forecast: Changes Castform's type and form to match the weather.

Moves

Moves Castform learns by level up in Ultra Sun / Ultra Moon

TM moves (32)

Castform can learn 32 moves from TMs in Ultra Sun / Ultra Moon: Work Up, Toxic, Hail, Hidden Power, Sunny Day, Ice Beam, Blizzard, Protect, Rain Dance, Frustration, Solar Beam, Thunderbolt, Thunder, Return, Shadow Ball, Double Team, Flamethrower, Sandstorm, Fire Blast, Facade, Rest, Attract, Thief, Round, Energy Ball, Scald, Thunder Wave, Psych Up, Swagger, Sleep Talk, Substitute, Confide.

Egg moves (10):Amnesia, Clear Smog, Cosmic Power, Disable, Future Sight, Guard Swap, Hex, Lucky Chant, Ominous Wind, Reflect Type.

Move tutor moves (7): Defog, Icy Wind, Last Resort, Shock Wave, Snore, Tailwind, Water Pulse.

Breeding & training

• Gender: 50% male, 50% female.
• Egg groups: Fairy, Amorphous.
• Egg cycles: 25 (steps to hatch, Scarlet/Violet: 3,200).
• Catch rate: 45 out of 255.
• Base friendship (Gen 8 onward): 50.
• Growth rate: Medium (1,000,000 experience points to reach level 100).
• Defeating it gives 1 HP effort value.
• Base experience yield: 147.

Pokédex entries

Its form changes depending on the weather. The rougher conditions get, the rougher Castform's disposition! (Ultra Moon)

Although its form changes with the weather, that is apparently the result of a chemical reaction and not the result of its own free will. (Ultra Sun)

Its form changes on its own, due to its cells' sensitive reactions to temperature and humidity. (Moon)

It changes its form depending on the weather. Changes in the temperature or humidity appear to affect its cellular structure. (Sun)

Castform borrows the power of nature to transform itself into the guises of the sun, rain, and snow-clouds. This Pokémon's feelings change with the weather. (Alpha Sapphire)

Castform's appearance changes with the weather. This Pokémon gained the ability to use the vast power of nature to protect its tiny body. (Ruby, Omega Ruby)

Names around the world

Trivia

• Lightest Pokémon in Gen 3: 0.8 kg.
• Lightest Normal type in Gen 3: 0.8 kg.
• Taller than 4% of all Pokémon (0.3 m).
• Heavier than 3% of all Pokémon (0.8 kg).
• Base stat total 420, ranked #562 of 1,025.
• One of 131 Normal-type Pokémon (counting dual types).
• One of 107 gray Pokémon.
• Number 100 of 135 Pokémon introduced in Generation 3 (Hoenn).
• Can learn 57 different moves in Ultra Sun / Ultra Moon.
• Catch rate 45: about 5.9% per Poké Ball at full health.
• Has 3 alternate forms.
• Appears in 12 distinct Pokédex entries.

Sources and fact-checking

• Stats, types, abilities, moves, evolutions, forms and Pokédex entries: PokéAPI open game data.
• Lore: written by pokee.si in our own words, researched from Bulbapedia: Castform (Pokémon), Serebii: Castform (Sword/Shield Pokédex layout; lists Brilliant Diamond locations, as Castform is not in Sword and Shield).
• Pronunciation (KAST-form): it follows how the English anime, games or official videos say it.

Last checked: 20 October 2026. Every sentence of the lore was checked against Bulbapedia, Serebii and the game data.

Explore

Normal-type Pokémon · Hoenn region guide · Forecast ability · Compare Castform · Full Pokédex · Type chart · All moves

Browse similar Pokémon

Gen 3 Normal-type Pokémon · Gen 3 Pokémon list · Gray Pokémon list · Fairy egg group · Amorphous egg group · Pokémon that start with C

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