phb 2014, 243
Fog Cloud
1-level Conjuration
Casting Time: 1 action
Range/Area: 120 feet
Components: Verbal, Somatic
Duration: Concentration, up to 1 hour
Damage/Effect: heavily obscured area
You create a 20 foot radius sphere of fog centered on a point within range. The sphere spreads around corners, and its area is heavily obscured. It lasts for the duration or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it.
At higher levels: When you cast this spell using a spell slot of 2nd level or higher, the radius of the fog increases by 20 feet for each slot level above 1st.
Available for: Druid, Ranger, Sorcerer, Wizard