Blazing orbs of fire plummet to the ground at four different points you can see within range. Each creature in a 40-foot-radius Sphere centered on each of those points makes a Dexterity saving throw. A creature takes 20d6 Fire damage and 20d6 Bludgeoning damage on a failed save or half as much damage on a successful one. A creature in the area of more than one fiery Sphere is affected only once.
A nonmagical object that isn't being worn or carried also takes the damage if it's in the spell's area, and the object starts burning if it's flammable.