Steam Fog

What is steam fog?

Steam fog forms when cold, dry air moves over a warmer, nonfrozen water surface. The water evaporates rapidly into the cold air, saturating it and rising like smoke—which is why it's also called "sea smoke." It's often shallow but can become dense and cover large areas. Think of it as the "steam" you see rising off a warm lake on a cold morning.

Also known as: sea smoke, evaporation fog

Learn more in the library

• Upslope, Steam, and Frontal Fog: Lesser-Known Fog Types →
• Fog Types and Rapid Visibility Deterioration at Destination Alternates →
• Fog Formation Types and IFR Departure Planning →

Related terms

• starter/generator
• static port
• station
• stationary front
• stick pusher
• stress risers
• structural icing
• subsonic