Elemental Weapon

2nd-Level Transmutation
Casting Time: 1 bonus action
Range: Touch
Components: VS
Duration: (C) 1 hour

Target. One weapon.

Effect. Choose one of the following damage types: acid, cold, fire, lightning, or thunder. For the duration, the weapon becomes a magic weapon and has a +1 bonus to attack rolls and deals an extra 1d4 damage of the chosen type when it hits. The bonus to attack rolls can stack with enhancements from magic weapons, to a maximum of +3.

At Higher Levels.

4th level: The bonus to attack rolls increases to +2 and the extra damage increases to 2d4.
6th level: The bonus increases to +3 and the extra damage increases to 3d4.
8th level or higher: The damage dice increase in size based on the level of the spell used: d6 at 8th level, d8 at 10th level, d10 at 11th level, and d12 at 12th level.

Source: PHB 237

Changelog