Weather can change move power, cause residual damage, activate Abilities, and affect several special moves. Rain commonly boosts Water moves and weakens Fire moves, while harsh sunlight does the opposite. Sandstorm can damage many non-immune Pokémon between turns and benefits certain Rock-type defenses in some generations. Snow or hail rules have changed across games; modern snow mechanics can boost Defense for Ice types, while older hail commonly caused chip damage. Weather usually lasts a limited number of turns unless a specific permanent or extended effect applies. Build with weather only when multiple team members benefit from it.
