Elemental Weapon (Cold)

You touch a nonmagical weapon. Until the spell ends, that weapon becomes a magic weapon with a +1 bonus to attack rolls and damage rolls. And on a successful attack, the weapon will do an additional 1d4 damage. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the bonus increases to +2, and do an additional 1d4 damage. When you use a spell slot of 6th level or higher, the bonus increases to +3 and do an additional 2d4 damage. When you use a spell slot of 8th level or higher, the bonus increases to +4 and do an additional 3d4 damage.