Difference Between Fog and Mist

Fog and Mist are both condensed water vapor clouds, i.e. water droplets, sitting on the surface of the earth in the atmosphere, somewhat restricting visibility. Sharing similar composition, there are slight differences in the density and extent to which visibility is reduced between fog and mist. Fog is denser than mist and thus has a greater effect on visibility, i.e. the former limits visibility to almost one kilometer, while the latter limits visibility to more than one kilometer.

Both sound similar, but there are some differences that differentiate both. Let’s learn the mist and fog difference to understand the meaning in detail.

Fog Definition

In Simple words, fog is a term that is used to describe condensed water vapor that is suspended in the atmosphere, close to the surface of the earth, forming an opaque sheet that limits visibility. It is a dynamic atmospheric phenomenon that is greatly influenced by neighboring bodies of water, wind speed, topography.

Air can hold some amount of water. Air becomes more humid when there is more amount of water and after a certain point it begins to cool down and, as the temperature reaches its dew point, it begins to condense and fog is formed.

Mist Definition

Mist is an atmospheric phenomenon created at the surface of the earth by tiny water vapor suspended in the atmosphere, which in some way restricts visibility. This is caused by inversion of temperature, volcanic activity, increases in humidity. The chemical cycle that transforms mist into the water globules is called dispersion.

Mist is often seen when warm, moist air experiences untimely cooling, i.e. when droplets of warm water are suddenly cooled down, the droplets become visible to us. The most common form of mist in the winter time is exhaled air.

Mist vs Fog





A thick low-lying cloud, appearing at the surface level, that is composed of tiny dewdrops, held over in the air.

The cloud formed out of small water droplets held over in the atmosphere at the ground level, due to temperature inversion or variation in humidity.


Density is very high

Density is Comparatively low


Visible up to one kilometer

Visible to more than one kilometer.


It persists for longer period.

It persists for short time.

Key Points:

Fog: If cloud-like aggregated water droplets are seen within one kilometer, it is said to be fog.

Mist: If cloud-like aggregated water droplets are seen beyond one kilometer, it is said to be mist.

FAQ (Frequently Asked Questions)

1. What is the Difference Between Fog and Mist?

Fog is a cloud that reaches ground level, even though that "ground" is a mountain top or a hill. Mist occurs when water droplets are suspended in the air by inversion of temperature, volcanic activity, or moisture changes. Fog is denser than mist and is more likely to last longer.

2. What Causes Fog and Mist?

Mist often develops when warmer air over water suddenly encounters the cooler land surface. Mist is small droplets of water that hang in the air. As warmer water is rapidly cooled in the air, these droplets shape, causing it to transform from invisible gas to tiny visible droplets. Mist isn't as thick as fog