Difference Between Fog and Mist

The main difference between fog and mist is that fog is denser and lasts longer than mist.

Both fog and mist refer to a cloud of tiny water droplets suspended in the atmosphere. Moreover, fog and mist are formed the same way; however, they are not the same. Since mist is less dense than fog, you can see more clearly through mist. Therefore, there is a difference between fog and mist in terms of their thickness and visibility range.

Key Areas Covered

1. What is Fog 
    – Definition, Characteristics, Visibility
2. What is Mist
    – Definition, Characteristics, Visibility
3. What is the Difference Between Fog and Mist
     – Comparison of Key Differences

Key Terms

Fog, Mist

What is Fog

Fog is a thick cloudlike mass or layer of tiny water droplets near the surface of the Earth, reducing visibility. It is usually very difficult to see through a fog as fog reduces visibility to less than 1km. That means; it will prevent you from seeing further away than 1km from where you are. Even big objects like ships or mountains, or monuments like London Bridge or Statue of Liberty are difficult to see through a fog. Moreover, it can even cause vehicular accidents on the road.

Fog is actually a cloud on the ground, made up of tiny water droplets. These water droplets form when evaporated water is cooled. Depending on the way the water is cooled, there are different types of fogs. Radiation fog and advocation fog are the most common forms:

Radiation Fog – This is the fog that forms due to the cooling of the Earth’s surface at night. This is most common in autumn and early winter.

Advocation Fog – This is the fog that forms when cool air mixes with warm air. To be more specific, moist air passes over a cool surface by advection and is cooled. This mostly occurs at sea.

There are also other types of fogs as steam fog, hail fog, and ice fog. In general, fog forms when there is a difference between the ground and the air. 

What is Mist

Mist is a cloud of tiny water droplets suspended in the atmosphere, limiting the visibility. These water droplets are formed when warmer water in the air is cooled rapidly, changing invisible gas to tiny visible water droplets. It is a part of natural weather. Mist forms when warmer air over water suddenly encounters the cooler surface of the land or when warm air from land suddenly encounters cooler air over the ocean. You can also observe mist when you exhale air in the winter, or when you throw water onto a very hot surface. You can also see mist near shores or at the top of the mountains. Volcanic activity can also cause mists. Volcanic mists are emitted by steam vents or cracks in the Earth’s surface around active volcanos.

When compared to fog, mist is less dense; there are more water molecules in the same amount of space in a fog.  Moreover, you can see more clearly through mist, in comparison to fog (usually visibility remaining above 1 km). In addition, a mist can dissipate more quickly than a fog.

Difference Between Fog and Mist

Definition

Fog is a thick cloudlike mass or layer of tiny water droplets near the surface of the Earth, reducing visibility, while mist is a cloud of tiny water droplets suspended in the atmosphere, limiting the visibility.

Visibility Range

Moreover, fog reduces visibility to less than 1Km, whereas mist usually has visibility above 1km.

Thickness

Generally, fog is denser and thicker than mist.

Duration

A mist can dissipate more quickly than a fog.

Conclusion

The main difference between fog and mist is that fog is denser and lasts longer than mist. Moreover, since mist is less dense than fog, you can see more clearly through mist. Fog will prevent you from seeing further away than 1km from where you are while mist will allow you to see further away than 1km.

Reference:

1. “What Is Mist?” Earth.com, Available here.
2. “Fog.” National Geographic Society, 9 Oct. 2012, Available here.

Image Courtesy:

1. “10671” (CC0) via Pxhere
2. “Herbert Lake beim Icefields Parkway” By Florian Fuchs (CC BY 3.0) via Commons Wikimedia