Choose a point you can see on the ground within range. The ground bursts with molten geysers in a 40 foot cube centered on that point. Each creature in that area must make a Dexterity saving throw. A creature takes 6d6 fire damage on a failed save, or half as much damage on a successful one.

Cracks and fissures filled with molten lava open up in the area and churn the remaining solid earth, making the ground in the area difficult terrain until the spell ends. Any creature that enters the spell's area for the first time on a turn or ends its turn in the area must make a Dexterity saving throw. A creature takes 6d6 fire damage on a failed save, or half as much on a successful save. Creatures that aren't in or on the ground automatically succeed on this saving throw, but prone creatures make this saving throw with disadvantage.

This spell ignites flammable objects in the area that aren’t being worn or carried. When the spell ends, the ground in the area cools and solidifies, becoming difficult terrain until cleared. Each 5-foot-square portion of ground in the area requires at least 10 minutes to clear using mason's tools.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the fire damage dealt increases by 1d6 for each slot level above 5th.