Weak toFightingGroundSteelWaterGrassPsychicFairy ×1.6

Attacker	Type	Moveset	DPS
Deoxys	Psychic	Zen HeadbuttPsycho Boost	37.1
Mewtwo	Psychic	ConfusionPsystrikeLegacy	30.3
Lucario	FightingSteel	Force PalmAura SphereLegacy	29.8
Kartana	GrassSteel	Razor LeafLeaf Blade	28.5
Pheromosa	BugFighting	Low KickFocus Blast	27.3
Tapu Lele	PsychicFairy	ConfusionNatures MadnessLegacy	27.3
Tinkaton	FairySteel	Fairy WindGigaton HammerLegacy	27.2
Terrakion	RockFighting	Double KickSacred SwordLegacy	27.2
Blaziken	FireFighting	CounterAura Sphere	27.0
Metagross	SteelPsychic	Bullet PunchMeteor MashLegacy	26.0
Alakazam	Psychic	ConfusionPsychicLegacy	25.9
Inteleon	Water	Water GunHydro CannonLegacy	25.7

Windy boosts the Psychic attacks above. Overcast and Partly cloudy boost Terrakion.

Level 40, 15 attack IV, costed against Terrakion's own defense and typing, one per evolution family.

Terrakion's moveset, CP and shiny All counters Raid board

Questions people ask

What is Terrakion weak to in Pokémon GO?

Terrakion takes 1.6 times from Fighting, Ground, Steel, Water, Grass, Psychic and Fairy.

What's the best counter to Terrakion?

Deoxys with Zen Headbutt and Psycho Boost, worth 37.1 damage per second against Terrakion's own defense. The full ranking is above.