Weak toRock ×2.56WaterElectric ×1.6

Attacker	Type	Moveset	DPS
Glimmora	RockPoison	Rock ThrowMeteor Beam	32.3
Rampardos	Rock	Smack DownRock Slide	32.0
Tyrantrum	RockDragon	Rock ThrowMeteor Beam	29.9
Gigalith	Rock	Lock OnMeteor BeamLegacy	29.9
Rhyperior	GroundRock	Smack DownRock WreckerLegacy	28.9
Terrakion	RockFighting	Smack DownRock Slide	28.4
Tyranitar	RockDark	Smack DownStone EdgeLegacy	27.3
Regieleki	Electric	Lock OnThunder CageLegacy	26.6
Lycanroc	Rock	Rock ThrowStone Edge	26.0
Aggron	SteelRock	Smack DownMeteor Beam	25.3
Aerodactyl	RockFlying	Rock ThrowRock Slide	25.0
Aurorus	RockIce	Rock ThrowMeteor Beam	24.9

Partly cloudy boosts the Rock attacks above. Clear and Windy boost Ho-Oh.

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

Ho-Oh's moveset, CP and shiny All counters Raid board

Questions people ask

What is Ho-Oh weak to in Pokémon GO?

Ho-Oh takes 2.56 times damage from Rock, and 1.6 times from Water and Electric.

What's the best counter to Ho-Oh?

Glimmora with Rock Throw and Meteor Beam, worth 32.3 damage per second against Ho-Oh's own defense. The full ranking is above.