lairon evolves to aggron at lvl. 42 and aggron does not evolve
Aron will evolve into Lairon at level 32, then into Aggron at level 42.
it evolve at lv 43
Lairon will evolve to Aggron at level 42.
Lairon evolves into Aggron
you have to evolve aron to a aggron
It evolves into Aggron at level 42
it envolves into lairon then into aggron
Lairon evolves into Aggron starting at level 42. However, Aggron can temporarily Mega Evolve during battle while holding an Agrronite.
In Pokémon Sapphire you cannot find Aggron however you can find Aron in Granite Cave and in the Victory Road and then you can evolve it at Level 32 into Lairon and then you can evolve Lairon at Level 42 into Aggron additionally you can find wild Lairon in three areas within Victory Road in Pokémon Sapphire and then you can evolve it into Aggron.
Lairon evolves into Aggron starting at level 42.
He doesn't, he is the last stage, but Lairon evolves into Aggron at level 42. I advise waiting for him to evolve if you want some of his stronger moves, because Lairon learns then sooner. If not, then go ahead and evolve him.