Basic Rules (2014) - Modified
1-level Conjuration
You create a 20-foot-radius sphere of fog centered on a point within range. The area within the sphere is heavily obscured. It lasts for the duration or until a strong wind (such as one created by Gust of Wind) disperses it.
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.