Weak toFightingGround ×1.6

Attacker	Type	Moveset	DPS
Lucario	FightingSteel	Force PalmAura SphereLegacy	33.7
Pheromosa	BugFighting	Low KickFocus Blast	30.9
Terrakion	RockFighting	Double KickSacred SwordLegacy	30.7
Blaziken	FireFighting	CounterAura Sphere	30.5
Kartana	GrassSteel	Fury CutterSacred Sword	29.1
Groudon	Ground	Mud ShotPrecipice BladesLegacy	28.4
Conkeldurr	Fighting	Force PalmFocus Blast	28.1
Keldeo	WaterFighting	Low KickSacred Sword	27.9
Breloom	GrassFighting	Force PalmDynamic Punch	27.8
Urshifu	Fighting	CounterDynamic Punch	27.5
Eternatus	PoisonDragon	Poison JabDynamax CannonLegacy	27.4
Excadrill	GroundSteel	Mud SlapEarthquake	26.9

Overcast boosts the Fighting attacks above. Partly cloudy and Rainy boost Heliolisk.

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

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

Questions people ask

What is Heliolisk weak to in Pokémon GO?

Heliolisk takes 1.6 times from Fighting and Ground.

What's the best counter to Heliolisk?

Lucario with Force Palm and Aura Sphere, worth 33.7 damage per second against Heliolisk's own defense. The full ranking is above.