Flame Strike

You conjure a circle of destruction in a 10-foot radius. Moments later, the circle erupts into a 40-foot-high cylinder of fire. Each creature within range must make a Dexterity saving throw. A creature takes 5d8 fire damage, or half as much damage on a successful one. The ground in that area then burns for three rounds. While burning, the area counts as difficult terrain, and a creature takes 2d8 fire damage when it enters the burning area for the first time, or if it ends its turn there.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage of both effects increases by 1d8 for each slot level above 4th.