Fog

Morning fog in park

Fog near a tree.

Fog in autumn forest

Fog is a meteorological phenomenon. It is stratus clouds on the surface of the Earth. Fog may appear on land or sea and it usually lowers visibility (makes it hard to see very far). When the air chills, moisture will turn to fog.

Fog is made up of tiny water droplets or, in very cold conditions, ice crystals. When seen on a high speed camera, (a special camera that takes many frames and can view videos at very low speed) it looks like hundreds of small water droplets moving through the air. These water droplets make up the fog or mist.

There are many types of fog, classified according to what makes the condensation. They include evaporation fog, advection fog, radiation fog, and upslope fog. The thickness of fog varies depending on the atmosphere, temperature, weather and location.

Crepuscular rays made by tree shadows over fog
The morning fog in the Rhine Valley between Lienz / Altstätten and Rüthi.
Ground fog in East Frisia (Moordorf)
A foggy sunrise

Fog Media

View from Blassenstein mountain near Scheibbs (Lower Austria) to the west, with fog over Erlauf valley and Danube
A massive fog bank over Twentynine Palms, California, covers the entire city as it begins to rise and join the clouds above it.
Fog dissipating over Koblenz, Germany
A foggy Aura River in Turku, Finland
Minute droplets of water constitute this after-dark radiation fog, with an ambient temperature of −2 °C (28 °F). Their motion trails are captured as streaks.
A close-up view of water droplets forming fog. Those outside the camera lens's depth of field appear as orbs.
Advection fog layer in San Francisco with the Golden Gate Bridge and skyline in the background
Aerial video of freezing fog in the Okanagan Highlands
Свјетлопис аутопута у Србији, магле и Сунца.
Light fog reduces visibility on a suburban street, rendering the cyclist very hazy at about 200 m (220 yd). The limit of visibility is about 400 m (440 yd), which is before the end of the street.