Weak toGround ×1.6

Attacker	Type	Moveset	DPS
Groudon	Ground	Mud ShotPrecipice BladesLegacy	26.8
Eternatus	PoisonDragon	Poison JabDynamax CannonLegacy	25.8
Excadrill	GroundSteel	Mud SlapEarthquake	25.4
Mamoswine	IceGround	Mud SlapHigh Horsepower	25.0
Regigigas	Normal	Hidden PowerCrush GripLegacy	24.1
Rhyperior	GroundRock	Mud SlapEarthquake	24.1
Garchomp	DragonGround	Mud ShotEarthquake	23.9
Landorus	GroundFlying	Mud ShotEarth Power	23.8
Blacephalon	FireGhost	IncinerateMind BlownLegacy	23.4
Krookodile	GroundDark	Mud SlapEarthquake	23.0
Golurk	GroundGhost	Mud SlapEarth Power	21.9
Golem	RockGround	Mud SlapEarthquake	21.3

Clear boosts the Ground attacks above. Rainy boosts Mega Manectric.

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

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

Questions people ask

What is Mega Manectric weak to in Pokémon GO?

Mega Manectric takes 1.6 times from Ground.

What's the best counter to Mega Manectric?

Groudon with Mud Shot and Precipice Blades, worth 26.8 damage per second against Mega Manectric's own defense. The full ranking is above.