When no weather condition is under effect, Weather Ball deals Normal-type damage. During any weather condition, Weather Ball attacks with a different type and its base power doubles to 100. The type that Weather Ball is depends on the weather conditions at the time it is used. It will be:
Template:Breedlist
|-
| style="background: #FFF; font-family:monospace,monospace" | 0069
| style="background: #FFF; text-align: center;" |
| style="background: #FFF" | Bellsprout
| colspan="1" style="background:#3FA129; text-align: center;" | Grass || style="background:#9141CB" align="center" colspan="1" rowspan="1" | Poison
| style="background: #FFF" | Roserade
|-
| style="background: #FFF; font-family:monospace,monospace" | 0361
| style="background: #FFF; text-align: center;" |
| style="background: #FFF" | Snorunt
| colspan="2" style="background:#3DCEF3; text-align: center;" | Ice
| style="background: #FFF" | Castform Roserade
|-
| style="background: #FFF; font-family:monospace,monospace" | 0420
| style="background: #FFF; text-align: center;" |
| style="background: #FFF" | Cherubi
| colspan="2" style="background:#3FA129; text-align: center;" | Grass
| style="background: #FFF" | Castform Roserade
|-
| style="background: #FFF; font-family:monospace,monospace" | 0425
| style="background: #FFF; text-align: center;" |
| style="background: #FFF" | Drifloon
| colspan="1" style="background:#704170; text-align: center;" | Ghost || style="background:#81B9EF" align="center" colspan="1" rowspan="1" | Flying
| style="background: #FFF" | Castform
|-
| colspan="6" | Bold indicates a Pokémon which gets STAB from this move. Italic indicates a Pokémon whose evolution gets STAB from this move. *Indicates Pokémon that can only learn the move through chain breeding.
|}
|}
Template:Breedlist
|-
| style="background: #FFF; font-family:monospace,monospace" | 0069
| style="background: #FFF; text-align: center;" |
| style="background: #FFF" | Bellsprout
| colspan="1" style="background:#3FA129; text-align: center;" | Grass || style="background:#9141CB" align="center" colspan="1" rowspan="1" | Poison
| style="background: #FFF" | Roserade
|-
| style="background: #FFF; font-family:monospace,monospace" | 0361
| style="background: #FFF; text-align: center;" |
| style="background: #FFF" | Snorunt
| colspan="2" style="background:#3DCEF3; text-align: center;" | Ice
| style="background: #FFF" | Castform Roserade, Baibanira
|-
| style="background: #FFF; font-family:monospace,monospace" | 0420
| style="background: #FFF; text-align: center;" |
| style="background: #FFF" | Cherubi
| colspan="2" style="background:#3FA129; text-align: center;" | Grass
| style="background: #FFF" | Castform Roserade
|-
| style="background: #FFF; font-family:monospace,monospace" | 0425
| style="background: #FFF; text-align: center;" |
| style="background: #FFF" | Drifloon
| colspan="1" style="background:#704170; text-align: center;" | Ghost || style="background:#81B9EF" align="center" colspan="1" rowspan="1" | Flying
| style="background: #FFF" | Castform
|-
| colspan="6" | Bold indicates a Pokémon which gets STAB from this move. Italic indicates a Pokémon whose evolution gets STAB from this move. *Indicates Pokémon that can only learn the move through chain breeding.
|}
|}
Bellsprout is the only Pokémon to learn Weather Ball through breeding that cannot have Castform as a parent.
Weather Ball can reach up to a base power of 225, with a combination of; Sunny Day and STAB from Ho-oh or Castform, or Rain Dance and STAB from Castform.
Despite Weather Ball becoming a Rock-type move in a sandstorm, Castform itself won't change form in this condition.