Pokémon Go’s latest event is “Steel Skyline,” an event that — you guessed it — boosts the spawn rates of some steel-type Pokémon (among others) from Sept. 30 until Oct. 7.
Pokémon Go ‘Steel Skyline’ event guide

Pokémon Go’s latest event is “Steel Skyline,” an event that — you guessed it — boosts the spawn rates of some steel-type Pokémon (among others) from Sept. 30 until Oct. 7.