Weak toGrassElectric ×1.6

Attacker	Type	Moveset	DPS
Regieleki	Electric	Lock OnThunder CageLegacy	31.1
Zeraora	Electric	Volt SwitchPlasma Fists	26.7
Kartana	GrassSteel	Razor LeafLeaf Blade	26.6
Zekrom	DragonElectric	Charge BeamFusion BoltLegacy	26.1
Xurkitree	Electric	Thunder ShockDischarge	25.8
Roserade	GrassPoison	Magical LeafLeaf Storm	22.7
Eternatus	PoisonDragon	Poison JabDynamax CannonLegacy	22.6
Deoxys	Psychic	Charge BeamThunderbolt	22.4
Electivire	Electric	Thunder ShockWild Charge	22.3
Zarude	DarkGrass	Vine WhipPower Whip	22.2
Rillaboom	Grass	Razor LeafFrenzy PlantLegacy	22.0
Raikou	Electric	Volt SwitchWild Charge	21.7

Rainy boosts the Electric attacks above. Rainy boosts Blastoise.

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

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

Questions people ask

What is Blastoise weak to in Pokémon GO?

Blastoise takes 1.6 times from Grass and Electric.

What's the best counter to Blastoise?

Regieleki with Lock On and Thunder Cage, worth 31.1 damage per second against Blastoise's own defense. The full ranking is above.