Weak toFire ×2.56Fighting ×1.6

Attacker	Type	Moveset	DPS
Blacephalon	FireGhost	IncinerateMind BlownLegacy	48.9
Reshiram	DragonFire	Fire FangFusion FlareLegacy	40.6
Chandelure	GhostFire	Fire SpinOverheat	37.2
Cinderace	Fire	Fire SpinPyroball	36.7
Volcarona	BugFire	Fire SpinOverheat	36.3
Darmanitan	Fire	Fire FangOverheat	36.1
Blaziken	FireFighting	Fire SpinBlast BurnLegacy	34.9
Moltres	FireFlying	Fire SpinOverheat	34.6
Volcanion	FireWater	IncinerateOverheat	34.3
Heatran	FireSteel	Fire SpinMagma StormLegacy	34.1
Flareon	Fire	Fire SpinOverheat	33.9
Delphox	FirePsychic	Fire SpinBlast BurnLegacy	33.6

Clear boosts the Fire attacks above. Clear and Snow boost Ferrothorn.

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

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

Questions people ask

What is Ferrothorn weak to in Pokémon GO?

Ferrothorn takes 2.56 times damage from Fire, and 1.6 times from Fighting.

What's the best counter to Ferrothorn?

Blacephalon with Incinerate and Mind Blown, worth 48.9 damage per second against Ferrothorn's own defense. The full ranking is above.