How to adjust the fog on your landscape in Unreal Engine
Default levels come with a certain amount of fog already turned on. Learn how to adjust this.
Adjust the fog density (thickness)
In your Outliner, look for the Lighting folder > ExponentialHeightFog
Go to Details > Exponential Height Fog Component section > Fog Density and increase/decrease the value.
Tips
Adjusting the fog density can also represent the amount of humidity your level has.
You can have the fog only show at the lowest levels by increasing the "Fog Height Falloff" value.
Change the color of the fog with:
Fog Inscattering Color
Sky Atmosphere Ambient Contribution Color Scale