Summer is a fire cloud, not just fire. Laser Ray works; summoned Fire Slugs have access to that spell as well. In fact, you can find a ring that has Summon Fire Slug on it, but I can't remember where you get the ring--I think it's a quest reward. There's also the Aero spell Vaporize; if you have that spell just chuck a fire grenade and then use Vaporize on the fire. If you don't have the spell, Ovis in Driftwood square sells it. He also sells an Air wand with that spell on it, but that's more expensive than simply buying the skill book.
Spring is blood, Fall is a static cloud (just shoot a static cloud arrow), Winter is ice (ice arrow or Hydro spell).
