Cold Snap

The temperature suddenly drops within a 30 ft. radius sphere of a point you can see within range. Creatures within the area of effect must make a Constitution saving throw or take 4d6 cold damage. Creatures within the area that are chilled or wet become frozen on a failed saving throw, assuming the effects of the petrified until thawed or broken free. A frozen creature is freed upon taking bludgeoning or fire damage, or upon using its action to succeed on a Strength (Athletics) check against your spell save DC.

Any nonmagical surface within the radius becomes coated in ice, becoming difficult terrain until it thaws.