Weak toBugGhostGrassElectricDark ×1.6

Attacker	Type	Moveset	DPS
Regieleki	Electric	Lock OnThunder CageLegacy	28.3
Kartana	GrassSteel	Fury CutterLeaf Blade	24.4
Zeraora	Electric	Volt SwitchPlasma Fists	24.3
Blacephalon	FireGhost	AstonishShadow Ball	24.1
Zekrom	DragonElectric	Charge BeamFusion BoltLegacy	23.7
Xurkitree	Electric	Thunder ShockDischarge	23.4
Pheromosa	BugFighting	Bug BiteBug Buzz	23.2
Darkrai	Dark	SnarlShadow Ball	21.7
Chandelure	GhostFire	HexShadow Ball	21.5
Gengar	GhostPoison	LickShadow BallLegacy	21.5
Absol	Dark	SnarlBrutal SwingLegacy	21.0
Roserade	GrassPoison	Magical LeafLeaf Storm	20.6

Rainy boosts the Electric attacks above. Rainy and Windy boost Mega Starmie.

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

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

Questions people ask

What is Mega Starmie weak to in Pokémon GO?

Mega Starmie takes 1.6 times from Bug, Ghost, Grass, Electric and Dark.

What's the best counter to Mega Starmie?

Regieleki with Lock On and Thunder Cage, worth 28.3 damage per second against Mega Starmie's own defense. The full ranking is above.