Weather & Terrain — Complete Reference

01At a glance

Weather and terrain are the two field-state systems in modern Pokémon. They overlap — both last 5 turns by default, both can be extended with an item, and both interact with abilities — but they affect different things.

Weather affects every Pokémon on the field (with a few type immunities to chip). Terrain only affects grounded Pokémon (Flying-types, Levitate, Air Balloon, Magnet Rise are all unaffected). Both can be active at the same time on the same turn.

02The five weathers

Each weather is a global field state. It boosts certain types, weakens others, and may chip non-immune Pokémon at the end of every turn.

Sun (Sunny Day / Drought)

• Boosts: Fire moves × 1.5.
• Weakens: Water moves × 0.5.
• Misc: Solar Beam / Solar Blade skip charge turn. Synthesis, Moonlight, Morning Sun recover 2/3 max HP instead of 1/2. Thunder accuracy drops to 50%.
• Counters: Cloud Nine and Air Lock abilities suppress weather effects entirely while their bearer is on the field.

Rain (Rain Dance / Drizzle)

• Boosts: Water moves × 1.5.
• Weakens: Fire moves × 0.5.
• Misc: Thunder and Hurricane have 100% accuracy. Solar Beam halved BP (60 instead of 120). Synthesis / Moonlight / Morning Sun recover 1/4 max HP.

Sandstorm (Sand Stream)

• Damages: 1/16 max HP per turn to all non-Rock/Ground/Steel Pokémon.
• Boosts: Rock-type Pokémon get a 1.5× Special Defense boost in sand (Gen 4+).
• Misc: Solar Beam halved BP. Weather Ball becomes Rock-type with 100 BP.
• Iconic users: Tyranitar (Sand Stream auto-set), Hippowdon (Sand Stream secondary).

Hail (Hail / Snow Warning) — Gen 3-8

• Damages: 1/16 max HP per turn to all non-Ice Pokémon.
• Boosts: Blizzard has 100% accuracy. Aurora Veil can only be set under hail/snow.
• Misc: Solar Beam halved BP. Defog removes hail (Gen 6+).

Snow (Snow Warning) — Gen 9

• Replaces hail in Gen 9. No more 1/16 chip damage.
• Boosts: Ice-type Pokémon get a 1.5× Defense boost (NOT Sp.Def — important).
• Misc: Blizzard 100% accuracy and Aurora Veil enabling carry over.
• Iconic users: Cetitan (Slush Rush + bulk), Baxcalibur (Thermal Exchange — separate ability), Iron Bundle (Snow Warning team enabler).

03Weather setters — moves and abilities

Weather can be set by an ability (auto-sets on switch-in) or by a move. Move-set weather lasts 5 turns (8 with rock); ability-set weather works the same in Gen 6+.

Weather-setting abilities

Weather-setting moves

04Weather-dependent abilities

The big four Speed-doubling abilities are the engine of weather offense. Each doubles Speed under a specific weather, turning slow Pokémon into fast sweepers.

Other weather-conditional abilities

• Solar Power — × 1.5 Sp.Atk in sun, costs 1/8 HP per turn. Charizard, Heliolisk.
• Flower Gift — × 1.5 Atk and Sp.Def to allies in sun. Cherrim.
• Hydration — cures status at end of turn in rain. Manaphy, Vaporeon (HA).
• Dry Skin — heals 1/8 HP in rain, takes 1/8 in sun. Negates Water damage entirely. Toxicroak.
• Rain Dish — heals 1/16 HP per turn in rain.
• Ice Body — heals 1/16 HP per turn in hail/snow. Prevents hail damage to self.
• Sand Veil — × 0.8 evasion in sandstorm. Banned in most competitive formats (evasion clause).
• Sand Force — × 1.3 to Rock/Ground/Steel moves in sandstorm.
• Cloud Nine / Air Lock — suppress weather effects entirely while bearer is on the field.
• Forecast — Castform-only; changes typing to match weather (Fire in sun, Water in rain, Ice in hail).
• Protosynthesis — Gen 9 Paradox; in sun, boosts highest stat by 1.3× (1.5× for Speed). Triggers from Booster Energy item too.

05The four terrains

Terrains are the Gen 6 evolution of weather: shorter-range, more focused, and only affecting grounded Pokémon. Each terrain modifies one type of move and may block a specific class of move (sleep, priority, etc.).

Electric Terrain

• Boosts: Electric moves × 1.3 (× 1.5 pre-Gen 8) for grounded Pokémon.
• Blocks: Sleep — grounded Pokémon cannot fall asleep.
• Activates: Electric Seed (+1 Defense). Rising Voltage doubles BP. Thunderbolt, Discharge, Wild Charge get the boost.
• Setters: Electric Terrain (move), Electric Surge (Tapu Koko), Hadron Engine (Miraidon).

Psychic Terrain

• Boosts: Psychic moves × 1.3 (× 1.5 pre-Gen 8) for grounded Pokémon.
• Blocks: Priority moves cannot hit grounded Pokémon. Includes Sucker Punch, Bullet Punch, Aqua Jet, etc.
• Activates: Psychic Seed (+1 Sp.Def). Expanding Force doubles BP and becomes spread.
• Setters: Psychic Terrain (move), Psychic Surge (Tapu Lele, Indeedee).

Grassy Terrain

• Boosts: Grass moves × 1.3 (× 1.5 pre-Gen 8) for grounded Pokémon.
• Modifies: Earthquake, Bulldoze, Magnitude deal × 0.5 damage to grounded Pokémon (huge for bulky Grass cores).
• Heals: 1/16 max HP per turn to grounded Pokémon.
• Activates: Grassy Seed (+1 Def). Grassy Glide +1 priority for grounded users.
• Setters: Grassy Terrain (move), Grassy Surge (Tapu Bulu, Rillaboom).

Misty Terrain

• Halves: Dragon moves × 0.5 against grounded Pokémon.
• Blocks: All status conditions (paralysis, sleep, freeze, burn, poison) on grounded Pokémon. Confusion is also blocked.
• Activates: Misty Seed (+1 Sp.Def). Misty Explosion × 1.5 BP.
• Setters: Misty Terrain (move), Misty Surge (Tapu Fini).

06Terrain setters

Terrain is set by a move (5 turns) or an auto-setting ability (5 turns from Gen 7+ on switch-in). The Terrain Extender held item extends to 8 turns.

07Weather vs terrain stacking

Weather and terrain do not conflict — both can be active simultaneously. They affect different things: weather hits the air, terrain hits the ground.

• Both can stack: a Pokémon can deal STAB-boosted Electric damage in Electric Terrain (× 1.3) plus rain (× 1.5 for Water) — though those are different types. The same physical attacker on Grassy Terrain in sand: Grass-type move boosted by Grassy Terrain (× 1.3) AND a 1/16 HP heal from Grassy Terrain end-of-turn AND 1/16 chip from sandstorm if not Rock/Ground/Steel.
• Conflicting setters: if rain ability and sun ability both switch in the same turn, only the latter to switch in "wins" — its weather replaces the previous one.
• Removing the other field state: Defog removes both terrain AND weather (Gen 6+). Specific moves like Steel Roller (terrain) or weather-replacing moves don't cross-affect.
• Suppression: Cloud Nine and Air Lock suppress weather effects only — terrain still works in their presence.

08Cross-gen evolution

Weather in Pokémon went through three eras: pre-Gen 6 (permanent), Gen 6+ (5 turns from abilities too), and Gen 9 (snow replacing hail). Terrain only exists from Gen 6 onward.

09Competitive impact

Weather and terrain define entire archetypes. Setting either changes which Pokémon are good — Sand teams, Rain teams, Sun teams have been competitive archetypes since Gen 2. Terrain teams emerged in Gen 6.

Iconic weather/terrain teams across gens

• Gen 2 sand: Tyranitar / Steelix balance teams.
• Gen 4 hail: Abomasnow + Walrein/Glaceon stall.
• Gen 5 sand: Tyranitar + Excadrill (Sand Rush) — likely the strongest weather offense ever made; got Excadrill Drill banned.
• Gen 5 rain: Politoed + Kingdra/Tornadus-Therian — auto-rain dominated OU until Drizzle was banned.
• Gen 6 sun: Venusaur + Charizard-Y duo (Drought).
• Gen 7 terrain: Tapu Koko / Tapu Lele / Tapu Bulu / Tapu Fini — every Tapu defines a different terrain archetype.
• Gen 8 grassy: Rillaboom + Cinderace + Urshifu cores in OU, dominant in VGC 2020-21.
• Gen 9 sun: Koraidon (Orichalcum Pulse) drives sun-based offense in Restricted formats.
• Gen 9 snow: Iron Bundle / Cetitan + Snow Warning Ninetales-A is a niche but functional archetype.

10Common misconceptions

• "Snow doesn't damage" — true in Gen 9 only. Hail (Gen 3-8) deals 1/16 chip. Modern videos using snow are post-Gen 9; older guides referring to hail damage are pre-Gen 9.
• "Levitate Pokémon ignore terrain" — correct. Levitate, Air Balloon, Magnet Rise, Flying-types — all ungrounded, all unaffected by terrain effects (boost, heal, status block).
• "Sand boosts Rock-type Defense" — wrong. Sandstorm boosts Rock-type Special Defense by × 1.5 (NOT Defense). Common confusion.
• "Weather always lasts 8 turns with the rock" — only when set by a move or by the Pokémon holding the rock. If a different Pokémon sets the weather, the rock-holder doesn't extend it unless it's the setter.
• "Cloud Nine kills the weather" — wrong. Cloud Nine and Air Lock suppress the effects while their bearer is on the field; the weather itself is still active. When the suppressor switches out, the weather resumes immediately for the remaining turns.
• "Terrain blocks all priority" — only Psychic Terrain blocks priority moves, and only against grounded Pokémon. Other terrains don't.
• "Misty Terrain blocks Toxic damage" — Misty Terrain prevents new statuses on grounded Pokémon, but a Pokémon already poisoned before terrain was set keeps taking damage.

11Where to go from here

Weather and terrain interact with the damage formula and Speed mechanics. The pages below cover those layers.

• Damage formula — Damage Formula covers exactly how weather modifiers slot into damage calculations.
• Speed mechanics — Speed Mechanics covers Swift Swim, Chlorophyll, Sand Rush, Slush Rush in the broader Speed context.
• Type chart — Type Chart covers immunity rules (Ground for sand, Ice for hail).
• Live data — Abilities Index for weather setters. Moves Index for terrain-modified moves like Rising Voltage and Expanding Force.
• Glossary — every term used above is defined in the Competitive Glossary.