Weak toFightingGroundFire ×1.6

Attacker	Type	Moveset	DPS
Blacephalon	FireGhost	IncinerateMind BlownLegacy	31.1
Lucario	FightingSteel	Force PalmAura SphereLegacy	26.4
Reshiram	DragonFire	Fire FangFusion FlareLegacy	25.8
Pheromosa	BugFighting	Low KickFocus Blast	24.1
Terrakion	RockFighting	Double KickSacred SwordLegacy	24.0
Blaziken	FireFighting	CounterAura Sphere	23.9
Chandelure	GhostFire	Fire SpinOverheat	23.6
Cinderace	Fire	Fire SpinPyroball	23.3
Volcarona	BugFire	Fire SpinOverheat	23.1
Darmanitan	Fire	Fire FangOverheat	23.0
Groudon	Ground	Mud ShotPrecipice BladesLegacy	22.2
Moltres	FireFlying	Fire SpinOverheat	22.0

Overcast boosts the Fighting attacks above. Snow boosts Orthworm.

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

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

Questions people ask

What is Orthworm weak to in Pokémon GO?

Orthworm takes 1.6 times from Fighting, Ground and Fire.

What's the best counter to Orthworm?

Blacephalon with Incinerate and Mind Blown, worth 31.1 damage per second against Orthworm's own defense. The full ranking is above.