Weak toFighting ×1.6

Attacker	Type	Moveset	DPS
Lucario	FightingSteel	Force PalmAura SphereLegacy	58.8
Pheromosa	BugFighting	Low KickFocus Blast	53.8
Terrakion	RockFighting	Double KickSacred SwordLegacy	53.6
Blaziken	FireFighting	CounterAura Sphere	53.1
Kartana	GrassSteel	Fury CutterSacred Sword	50.7
Conkeldurr	Fighting	Force PalmFocus Blast	49.0
Keldeo	WaterFighting	Low KickSacred Sword	48.5
Breloom	GrassFighting	Force PalmDynamic Punch	48.4
Urshifu	Fighting	CounterDynamic Punch	48.0
Eternatus	PoisonDragon	Poison JabDynamax CannonLegacy	47.7
Marshadow	FightingGhost	CounterClose Combat	46.9
Mewtwo	Psychic	CounterFocus BlastLegacy	46.7

Overcast boosts the Fighting attacks above. Partly cloudy boosts Tandemaus.

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

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

Questions people ask

What is Tandemaus weak to in Pokémon GO?

Tandemaus takes 1.6 times from Fighting.

What's the best counter to Tandemaus?

Lucario with Force Palm and Aura Sphere, worth 58.8 damage per second against Tandemaus's own defense. The full ranking is above.