Weak toIce ×2.56DragonFairy ×1.6

Attacker	Type	Moveset	DPS
Eternatus	PoisonDragon	Dragon TailDynamax CannonLegacy	33.1
Chien-Pao	DarkIce	Powder SnowAvalanche	32.2
Baxcalibur	DragonIce	Ice FangAvalanche	32.1
Mamoswine	IceGround	Powder SnowAvalanche	30.6
Weavile	DarkIce	Ice ShardAvalanche	30.1
Glaceon	Ice	Frost BreathAvalanche	29.7
Kyurem	DragonIce	Dragon BreathGlaciateLegacy	28.6
Jynx	IcePsychic	Frost BreathAvalanche	28.0
Vanilluxe	Ice	Frost BreathAvalancheLegacy	27.4
Frosmoth	IceBug	Powder SnowIce Beam	26.7
Porygon-Z	Normal	Lock OnBlizzard	26.2
Mewtwo	Psychic	Psycho CutIce Beam	26.1

Snow boosts the Ice attacks above. Clear and Windy boost Mega Garchomp.

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

Mega Garchomp's moveset, stats and CP All counters Raid board

Questions people ask

What is Mega Garchomp weak to in Pokémon GO?

Mega Garchomp takes 2.56 times damage from Ice, and 1.6 times from Dragon and Fairy.

What's the best counter to Mega Garchomp?

Eternatus with Dragon Tail and Dynamax Cannon, worth 33.1 damage per second against Mega Garchomp's own defense. The full ranking is above.