Weak toRockSteelWaterElectricIce ×1.6

Attacker	Type	Moveset	DPS
Regieleki	Electric	Lock OnThunder CageLegacy	65.2
Zeraora	Electric	Volt SwitchPlasma Fists	56.9
Zekrom	DragonElectric	Charge BeamFusion BoltLegacy	55.6
Xurkitree	Electric	Thunder ShockDischarge	55.0
Metagross	SteelPsychic	Bullet PunchMeteor MashLegacy	51.8
Inteleon	Water	Water GunHydro CannonLegacy	51.1
Kyogre	Water	WaterfallOrigin PulseLegacy	51.0
Tinkaton	FairySteel	Fairy WindGigaton HammerLegacy	50.4
Glimmora	RockPoison	Rock ThrowMeteor Beam	50.3
Rampardos	Rock	Smack DownRock Slide	49.8
Lucario	FightingSteel	Force PalmMeteor MashLegacy	49.2
Kyurem	DragonIce	Steel WingGlaciateLegacy	49.1

Rainy boosts the Electric attacks above. Partly cloudy and Windy boost Archen.

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

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

Questions people ask

What is Archen weak to in Pokémon GO?

Archen takes 1.6 times from Rock, Steel, Water, Electric and Ice.

What's the best counter to Archen?

Regieleki with Lock On and Thunder Cage, worth 65.2 damage per second against Archen's own defense. The full ranking is above.