Weak toGroundGhostFireDark ×1.6

Attacker	Type	Moveset	DPS
Blacephalon	FireGhost	IncinerateMind BlownLegacy	33.8
Reshiram	DragonFire	Fire FangFusion FlareLegacy	28.1
Chandelure	GhostFire	Fire SpinOverheat	25.7
Cinderace	Fire	Fire SpinPyroball	25.4
Volcarona	BugFire	Fire SpinOverheat	25.1
Darmanitan	Fire	Fire FangOverheat	25.0
Darkrai	Dark	SnarlShadow Ball	24.6
Gengar	GhostPoison	LickShadow BallLegacy	24.4
Blaziken	FireFighting	Fire SpinBlast BurnLegacy	24.2
Groudon	Ground	Mud ShotPrecipice BladesLegacy	24.2
Moltres	FireFlying	Fire SpinOverheat	23.9
Absol	Dark	SnarlBrutal SwingLegacy	23.9

Clear boosts the Fire attacks above. Snow and Windy boost Iron Crown.

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

Iron Crown's moveset, CP and shiny All counters Raid board

Questions people ask

What is Iron Crown weak to in Pokémon GO?

Iron Crown takes 1.6 times from Ground, Ghost, Fire and Dark.

What's the best counter to Iron Crown?

Blacephalon with Incinerate and Mind Blown, worth 33.8 damage per second against Iron Crown's own defense. The full ranking is above.