Weak toFlyingRockFirePsychic ×1.6

Attacker	Type	Moveset	DPS
Blacephalon	FireGhost	IncinerateMind BlownLegacy	52.4
Mewtwo	Psychic	ConfusionPsystrikeLegacy	45.1
Reshiram	DragonFire	Fire FangFusion FlareLegacy	43.5
Salamence	DragonFlying	Fire FangFly	40.1
Chandelure	GhostFire	Fire SpinOverheat	39.8
Moltres	FireFlying	Fire SpinFly	39.4
Cinderace	Fire	Fire SpinPyroball	39.2
Volcarona	BugFire	Fire SpinOverheat	38.8
Darmanitan	Fire	Fire FangOverheat	38.7
Yveltal	DarkFlying	GustOblivion WingLegacy	38.6
Alakazam	Psychic	ConfusionPsychicLegacy	38.5
Toucannon	NormalFlying	PeckBeak BlastLegacy	38.2

Clear boosts the Fire attacks above. Overcast and Rainy boost Ariados.

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

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

Questions people ask

What is Ariados weak to in Pokémon GO?

Ariados takes 1.6 times from Flying, Rock, Fire and Psychic.

What's the best counter to Ariados?

Blacephalon with Incinerate and Mind Blown, worth 52.4 damage per second against Ariados's own defense. The full ranking is above.