Mist is a phenomenon of small droplets suspended in air. It
can occur as part of natural weather or volcanic activity,
and is common in cold air above warmer water, in exhaled air
in the cold, and in a steam room of a sauna. It can also be
created artificially with aerosol canisters if the humidity
conditions are right.
The only difference between mist and fog is visibility.
This phenomenon is called fog if the visibility is one
kilometre (1,100 yards) or less (in the UK for driving
purposes the definition of fog is visibility less than 200
metres, for pilots the distance is 1 kilometre). Otherwise
it is known as mist. Seen from a distance, mist is bluish,
and haze is more brownish.
Religious connotations are associated with mist in some
cultures; it is used as a metaphor in 2 Peter 2:17.
Mist makes a beam of light visible from the side via
refraction and reflection on the suspended water droplets.
"Scotch mist" is a light steady drizzle, the name being
typical of the Scottish penchant for understatement (and of
Mist usually occurs near the shores, and is often
associated with fog. Mist can be as high as mountain tops
when extreme temperatures are low.
Freezing mist is similar to freezing fog, only the
density is less and the visibility greater. When mist falls
below 0 degrees Celsius in temperature it becomes known as
Fog is a collection of water droplets or ice crystals
suspended in the air at or near the Earth's surface. While
fog is a type of a cloud, the term "fog" is typically
distinguished from the more generic term "cloud" in that fog
is low-lying, and the moisture in the fog is often generated
locally (such as from a nearby body of water, like a lake or
the ocean, or from nearby moist ground or marshes).
Fog is distinguished from mist only by its density, as
expressed in the resulting decrease in visibility: Fog
reduces visibility to less than 1 km (5/8 statute mile),
whereas mist reduces visibility to no less than 1 km (5/8
statute mile). For aviation purposes in the UK, a visibility
of less than 2 km but greater than 999 m is considered to be
mist if the relative humidity is 95% or greater - below 95%
haze is reported.
Haze is traditionally an atmospheric phenomenon where
dust, smoke and other dry particles obscure the clarity of
the sky. The World Meteorological Organization manual of
codes includes a classification of horizontal obscuration
into categories of fog, ice fog, steam fog, mist, haze,
smoke, volcanic ash, dust, sand and snow. Sources for
haze particles include farming (ploughing in dry weather),
traffic, industry, and wildfires.
Seen from afar (e.g. approaching airplane) and depending
upon the direction of view with respect to the sun, haze may
appear brownish or bluish, while mist tends to be
bluish-grey. Whereas haze often is thought of as a
phenomenon of dry air, mist formation is a phenomenon of
humid air. However, haze particles may act as condensation
nuclei for the subsequent formation of mist droplets; such
forms of haze are known as "wet haze."