Cold Snap

You blow your breath outward, causing the temperature to drop. Then, you extend your arm and snap your fingers. A bluster of snow shoots forth from your outstretched hand. Each creature in a 15-foot cone must make a Dexterity saving throw. A creature takes 3d6 cold damage on a failed save, or half as much damage on a successful one. The ground in the area flash freezes over and becomes slippery, making it difficult terrain until it melts at the beginning of your next turn. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d6 for each slot level above 1st, And the difficult terrain lasts an extra turn for each level.