Weak toBugGhostIceDragonDarkFairy ×1.6

Attacker	Type	Moveset	DPS
Eternatus	PoisonDragon	Dragon TailDynamax CannonLegacy	25.1
Baxcalibur	DragonIce	Ice FangGlaive RushLegacy	19.4
Blacephalon	FireGhost	AstonishShadow Ball	18.8
Rayquaza	DragonFlying	Dragon TailBreaking SwipeLegacy	18.4
Haxorus	Dragon	Dragon TailBreaking SwipeLegacy	18.4
Palkia	WaterDragon	Dragon TailDraco Meteor	18.4
Salamence	DragonFlying	Dragon TailDraco Meteor	18.2
Pheromosa	BugFighting	Bug BiteBug Buzz	18.2
Dragapult	DragonGhost	Dragon TailShadow Ball	17.5
Dragonite	DragonFlying	Dragon TailDraco MeteorLegacy	17.4
Chien-Pao	DarkIce	SnarlBlizzard	17.1
Garchomp	DragonGround	Dragon TailBreaking Swipe	17.0

Windy boosts the Dragon attacks above. Windy boosts Mega Latias.

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

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

Questions people ask

What is Mega Latias weak to in Pokémon GO?

Mega Latias takes 1.6 times from Bug, Ghost, Ice, Dragon, Dark and Fairy.

What's the best counter to Mega Latias?

Eternatus with Dragon Tail and Dynamax Cannon, worth 25.1 damage per second against Mega Latias's own defense. The full ranking is above.