Sunshower is a weather that switches FDef and SDef and triggers a handful of abilities (mostly crummy besides PMokou's x2 speed in sunshower one). Extra Ran is the only auto-inducer, though Speed Renko can manually and permanently set it.
Kouryuu is a terrain that prevents hold items from doing anything and triggers a couple unremarkable abilities that I don't remember the names and users of. It can only be set manually.
