Weak toBugGhostDark ×1.6

Attacker	Type	Moveset	DPS
Blacephalon	FireGhost	AstonishShadow Ball	21.5
Pheromosa	BugFighting	Bug BiteBug Buzz	20.8
Darkrai	Dark	SnarlShadow Ball	19.4
Chandelure	GhostFire	HexShadow Ball	19.2
Gengar	GhostPoison	LickShadow BallLegacy	19.2
Absol	Dark	SnarlBrutal SwingLegacy	18.8
Eternatus	PoisonDragon	Poison JabDynamax CannonLegacy	18.4
Dragapult	DragonGhost	AstonishShadow Ball	18.3
Hoopa	PsychicGhost	AstonishShadow Ball	18.0
Lunala	PsychicGhost	Shadow ClawShadow Ball	18.0
Gholdengo	SteelGhost	HexShadow Ball	17.9
Zoroark	Dark	SnarlFoul Play	17.9

Fog boosts the Ghost attacks above. Windy boosts Cresselia.

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

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

Questions people ask

What is Cresselia weak to in Pokémon GO?

Cresselia takes 1.6 times from Bug, Ghost and Dark.

What's the best counter to Cresselia?

Blacephalon with Astonish and Shadow Ball, worth 21.5 damage per second against Cresselia's own defense. The full ranking is above.