Weak toFighting ×1.6

Attacker	Type	Moveset	DPS
Lucario	FightingSteel	Force PalmAura SphereLegacy	31.6
Pheromosa	BugFighting	Low KickFocus Blast	29.0
Terrakion	RockFighting	Double KickSacred SwordLegacy	28.8
Blaziken	FireFighting	CounterAura Sphere	28.6
Kartana	GrassSteel	Fury CutterSacred Sword	27.3
Conkeldurr	Fighting	Force PalmFocus Blast	26.4
Keldeo	WaterFighting	Low KickSacred Sword	26.1
Breloom	GrassFighting	Force PalmDynamic Punch	26.1
Urshifu	Fighting	CounterDynamic Punch	25.9
Eternatus	PoisonDragon	Poison JabDynamax CannonLegacy	25.7
Marshadow	FightingGhost	CounterClose Combat	25.3
Mewtwo	Psychic	CounterFocus BlastLegacy	25.2

Overcast boosts the Fighting attacks above. Partly cloudy boosts Porygon2.

Level 40, 15 attack IV, costed against Porygon2's own defense and typing, one per evolution family.

Porygon2's moveset, CP and shiny All counters Raid board

Questions people ask

What is Porygon2 weak to in Pokémon GO?

Porygon2 takes 1.6 times from Fighting.

What's the best counter to Porygon2?

Lucario with Force Palm and Aura Sphere, worth 31.6 damage per second against Porygon2's own defense. The full ranking is above.