Weak toPoisonSteel ×1.6

Attacker	Type	Moveset	DPS
Eternatus	PoisonDragon	Poison JabSludge Bomb	37.6
Metagross	SteelPsychic	Bullet PunchMeteor MashLegacy	36.9
Tinkaton	FairySteel	Fairy WindGigaton HammerLegacy	35.9
Naganadel	PoisonDragon	Poison JabSludge Bomb	35.7
Lucario	FightingSteel	Bullet PunchMeteor Mash	34.1
Nihilego	RockPoison	Poison JabSludge Bomb	33.9
Roserade	GrassPoison	Poison JabSludge Bomb	33.1
Dialga	SteelDragon	Metal ClawIron Head	32.7
Munkidori	PoisonPsychic	Poison JabSludge Bomb	32.5
Regigigas	Normal	Hidden PowerCrush GripLegacy	32.1
Genesect	BugSteel	Metal ClawMagnet Bomb	31.9
Revavroom	SteelPoison	Poison JabGunk Shot	31.2

Snow boosts the Steel attacks above. Overcast boosts Granbull.

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

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

Questions people ask

What is Granbull weak to in Pokémon GO?

Granbull takes 1.6 times from Poison and Steel.

What's the best counter to Granbull?

Eternatus with Poison Jab and Sludge Bomb, worth 37.6 damage per second against Granbull's own defense. The full ranking is above.