Weather

Weather conditions are a feature that was implemented into the Pokémon games in Generation II, and expanded upon in Generations III and IV. During these games, weather depended upon where a battle took place, or even whether a Pokémon had used a specific move.

Current Conditions

Intense sunlight

• Effect: Powers up Fire-type moves, weakens Water-type moves, allows immediate firing of Solarbeam. Causes effects for Pokémon with some abilities. Changes Weather Ball to a Fire-type move, and Castform to its Fire-type form.
• Activating move: Sunny Day.
• Activating ability: Drought.
• Routes where it is encountered naturally: Eastern Hoenn Water routes (after Groudon is awakened, before it is captured) (Ruby/Emerald); Routes where Terra Cave appears (Emerald).

Heavy rain

• Effect: Powers up Water-type moves, weakens Fire-type moves, weakens the power of Solarbeam. Causes effects for Pokémon with some abilities. Changes Weather Ball to a Water-type move, and Castform to its Water-type form.
• Activating move: Rain Dance.
• Activating ability: Drizzle.
• Routes where it is encountered naturally: Route 119 (some days) (Ruby/Sapphire/Emerald); Route 120 (always) (Ruby/Sapphire/Emerald); Route 123 (some days) (Ruby/Sapphire/Emerald); eastern Hoenn Water routes (after Kyogre is awakened, before it is captured) (Sapphire/Emerald); Routes where Marine Cave appears (Emerald).

Sandstorm

• Effect: Damages Pokémon not of the Rock-, Ground-, or Steel-types. Causes effects for Pokémon with some abilities. Changes Weather Ball to a Rock-type move, but does not change Castform's form.
• Activating move: Sandstorm.
• Activating ability: Sand Stream.
• Routes where it is encountered naturally: Route 111 (in the desert) (Ruby/Sapphire/Emerald).

Hailstorm

• Effect: Damages Pokémon not of the Ice-type. Changes Weather Ball to an Ice-type move, and Castform to its Ice-type form.
• Activating move: Hail.
• Activating ability: Snow Storm (no official English name).
• Routes where it is encountered naturally: None so far.

Snow

• Effect: None known.
• Activating move: None known.
• Activating ability: None so far.
• Routes where it is encountered naturally: Route 217 (Diamond/Pearl).

Fog

• Effect: None known.
• Clearing move: HM05: Fog Clear
• Activating ability: None so far.
• Routes where it is encountered naturally: (Diamond/Pearl).

History

Generation II

In the second-generation games, three moves were introduced that could change the weather during a battle to alter the playing field slightly. These moves were Sunny Day, which created five turns worth of intense sunlight; Rain Dance, which gave five turns of heavy rain; and Sandstorm, which made a wild sandstorm that lasted for the same amount of turns. These three moves could change the course of a battle, with intense sun and heavy rain powering up Fire- and Water-type moves, and powering down the other, respectively, and a sandstorm damaging any Pokémon not of the Rock-, Ground-, or Steel-types slightly.

Generation III

In the third generation, the title Pokémon of the three Hoenn-based versions had weather-related abilities. Groudon's ability allowed for intense sunlight to fill the arena until the battle ended, or another weather effect took its place. Likewise, its counterpart, Kyogre's ability made heavy rain that lasted until the end of the battle or until another weather effect superceded it. Emerald Version's mascot, however, had a different way of affecting the playing field. While Rayquaza is battling, all effects of the weather are essentially negated, though the actual sunlight/rain/sandstorm/hail remains going.

Another Pokémon, one which was not available in Ruby or Sapphire without trading, also had a weather-based ability. Tyranitar, once fully evolved from a Larvitar captured in FireRed or LeafGreen, has the ability Sand Stream, which causes a sandstorm that lasts until the end of the battle or until another weather-changing move is made. This makes it almost useless for a Tyranitar to have the move Sandstorm itself, as the sandstorm is automatically activated as it comes into battle.

Ruby and Sapphire also debuted another weather-changing move, Hail, which, like Sunny Day, Rain Dance, and Sandstorm before it, changes the weather for five turns, this time to an icy hailstorm. However, this move, and weather effect, have more in common with Sandstorm than with the other two. For the five turns that it's hailing, all Pokémon who are not Ice-type are damaged. To many, this is quite useless, and often annoying, as it only allows for the safety of one type of Pokémon, as opposed to a sandstorm's guaranteeing safety for three, often more physically powerful, types.

Castform

Also in Generation III, one of the 135 Pokémon released was a quirky little Normal-type called Castform. When in a battle where no weather effects were present, Castform is quite unremarkable. However, when any of the effects besides a sandstorm are applied, Castform's type and shape change to match the weather, due to its ability, Forecast. Also, when it is levelled up, it learns a move called Weather Ball, which also changes type with the weather. Unlike Castform's ability, Forecast, Weather Ball's type differs even in a sandstorm, becoming a Rock-type move.

Generation IV

Within the fourth generation, the weather effects seem to be going strong. At one point in Sinnoh, it is actually possible to travel on a route covered in snow. Whether this weather has effects on moves, types, or Castform is yet to be demonstrated. Also in Genetation IV, a new ability was released that serves much like Drought, Drizzle, and Sand Stream, excepting the fact that it permanently activates a hailstorm instead of sunlight, rain, or sandstorm.