Weak toGround ×1.6

Attacker	Type	Moveset	DPS
Groudon	Ground	Mud ShotPrecipice BladesLegacy	30.2
Eternatus	PoisonDragon	Poison JabDynamax CannonLegacy	29.1
Excadrill	GroundSteel	Mud SlapEarthquake	28.7
Mamoswine	IceGround	Mud SlapHigh Horsepower	28.2
Regigigas	Normal	Hidden PowerCrush GripLegacy	27.2
Rhyperior	GroundRock	Mud SlapEarthquake	27.2
Garchomp	DragonGround	Mud ShotEarthquake	26.9
Landorus	GroundFlying	Mud ShotEarth Power	26.8
Blacephalon	FireGhost	IncinerateMind BlownLegacy	26.4
Krookodile	GroundDark	Mud SlapEarthquake	25.9
Golurk	GroundGhost	Mud SlapEarth Power	24.7
Golem	RockGround	Mud SlapEarthquake	24.0

Clear boosts the Ground attacks above. Rainy boosts Mega Raichu Y.

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

Mega Raichu Y's moveset, stats and CP All counters Raid board

Questions people ask

What is Mega Raichu Y weak to in Pokémon GO?

Mega Raichu Y takes 1.6 times from Ground.

What's the best counter to Mega Raichu Y?

Groudon with Mud Shot and Precipice Blades, worth 30.2 damage per second against Mega Raichu Y's own defense. The full ranking is above.