Weak toGroundGhostFireDark ×1.6

Attacker	Type	Moveset	DPS
Blacephalon	FireGhost	IncinerateMind BlownLegacy	32.3
Reshiram	DragonFire	Fire FangFusion FlareLegacy	26.8
Chandelure	GhostFire	Fire SpinOverheat	24.6
Cinderace	Fire	Fire SpinPyroball	24.2
Volcarona	BugFire	Fire SpinOverheat	24.0
Darmanitan	Fire	Fire FangOverheat	23.9
Darkrai	Dark	SnarlShadow Ball	23.5
Gengar	GhostPoison	LickShadow BallLegacy	23.3
Blaziken	FireFighting	Fire SpinBlast BurnLegacy	23.1
Groudon	Ground	Mud ShotPrecipice BladesLegacy	23.1
Moltres	FireFlying	Fire SpinOverheat	22.9
Absol	Dark	SnarlBrutal SwingLegacy	22.8

Clear boosts the Fire attacks above. Snow and Windy boost Jirachi.

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

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

Questions people ask

What is Jirachi weak to in Pokémon GO?

Jirachi takes 1.6 times from Ground, Ghost, Fire and Dark.

What's the best counter to Jirachi?

Blacephalon with Incinerate and Mind Blown, worth 32.3 damage per second against Jirachi's own defense. The full ranking is above.