A foggy night… it’s hard to see… It’s the perfect set up for a spooky movie scene. But really, fog is just like a cloud on the ground. It’s made up of tiny droplets of water that float in the air.
Fog is caused by cooling of the air. And there are different kinds of fog.
The first, is radiation fog. This when you have a clear night… The ground gets cool… and there’s enough moisture for fog to develop. This is the most common type. Another is advection fog. This is when warm, moist air moves over a cold surface. We see this around here… it’s called sea fog, and it happens mainly during the winter time. And finally, we have evaporation fog or steam fog. This is when fog develops over warm water when it’s cold outside.
Fog can make it very hard to see. Visibility can be reduced to near zero at times. It’s hard… and dangerous to drive when it’s foggy. Airlines have to be careful too… some of the worst airplane crashes have happened when it was foggy.