Drought

All water, mist, or fog in a 20 foot emanation evaporates and disperses, and does so when the emanation enters its area or when it enters the emanation.

Whenever the Emanation enters a creature’s space and whenever a creature enters the Emanation or ends its turn there, the creature must make a Constitution saving throw. On a failed save, the creature takes 1d6 + 1 Fire damage. On a successful save, the creature takes half as much damage. A creature makes this save only once per turn.

Using a higher level spell slot. The Fire damage increases by 1d6 + 1 for each slot level above 2nd.