Weak toFightingRockGrassElectric ×1.6

Attacker	Type	Moveset	DPS
Regieleki	Electric	Lock OnThunder CageLegacy	46.9
Lucario	FightingSteel	Force PalmAura SphereLegacy	42.0
Zeraora	Electric	Volt SwitchPlasma Fists	40.3
Kartana	GrassSteel	Razor LeafLeaf Blade	40.2
Zekrom	DragonElectric	Charge BeamFusion BoltLegacy	39.4
Xurkitree	Electric	Thunder ShockDischarge	38.9
Pheromosa	BugFighting	Low KickFocus Blast	38.4
Terrakion	RockFighting	Double KickSacred SwordLegacy	38.3
Blaziken	FireFighting	CounterAura Sphere	38.0
Breloom	GrassFighting	Force PalmGrass KnotLegacy	36.0
Glimmora	RockPoison	Rock ThrowMeteor Beam	35.6
Rampardos	Rock	Smack DownRock Slide	35.2

Rainy boosts the Electric attacks above. Rainy and Snow boost Sealeo.

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

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

Questions people ask

What is Sealeo weak to in Pokémon GO?

Sealeo takes 1.6 times from Fighting, Rock, Grass and Electric.

What's the best counter to Sealeo?

Regieleki with Lock On and Thunder Cage, worth 46.9 damage per second against Sealeo's own defense. The full ranking is above.