Fog vs Haze vs Mist vs Smog

When to use each in English, with meaning, register, and examples.

Fog

Top 1,000 (very common)

Haze

Top 2,000 (common)

Mist

Top 2,000 (common)

Smog

Top 3,000 (common)
Most common: Fog
 FogHazeMistSmog
Pronunciation🇬🇧 //fɒg//🇺🇸 //fɔg//🇬🇧 //heɪz//🇺🇸 //heɪz//🇬🇧 //mɪst//🇺🇸 //mɪst//🇬🇧 //smɒg//🇺🇸 //smɔɡ//
MeaningA thick cloud of tiny water drops in the air that makes things hard to see.A thick mist in the air that makes it hard to see.A thick cloud of tiny water drops in the air.A type of air pollution that combines smoke and fog.
ExampleThe fog rolled in quickly, making the road almost invisible.The view was limited due to the morning haze over the hills.The mist rolled in from the sea, creating an eerie atmosphere.The city was covered in smog, making it hard to breathe.
RegisterNeutralNeutralNeutralNeutral
How commonTop 1,000 (very common)Top 2,000 (common)Top 2,000 (common)Top 3,000 (common)
Collocationsheavy fog, thick fog, foggy weather, dense fog, coastal fogthick haze, air quality and haze, haze of smoke, haze at sunrise, haze causing visibility issuesmorning mist, thick mist, heavy mist, gentle mist, coastal mistheavy smog, persistent smog, urban smog, smog alert, thick smog
Common mistakesConfused with 'smog', which is polluted fog, Using 'fog' for a light mist instead of a thick cloud, Incorrectly pluralizing 'fog' as 'fogs'Confusing 'haze' with 'fog' - haze is less dense., Using 'haze' inappropriately to refer to emotional states., Mixing it up with 'hazy' when describing something unclear.Confused with 'fog', which is denser., Using 'mist' when 'steam' is more appropriate., Saying 'the misty' instead of 'mist'.Confused with 'fog' - smog is polluted air, while fog is just water vapor., Using 'smog' to describe non-pollution related fog., Assuming 'smog' is only seen in industrial areas - it can occur in any polluted city.
Usage notesUse 'fog' in both literal and metaphorical senses. In formal writing, avoid using 'fog' figuratively unless context allows.Use 'haze' when describing poor visibility due to moisture or pollution. It's not typically used in formal writing.Used in both formal and informal contexts; appropriate for describing weather conditions. Avoid using in overly technical or scientific discussions.Use 'smog' in discussions about air quality or environmental issues. It's appropriate for both formal and informal contexts.

See it in real clips

Mist

Frequently asked questions: Fog vs Haze vs Mist vs Smog

What's the difference between Fog, Haze, Mist, and Smog?

Fog: A thick cloud of tiny water drops in the air that makes things hard to see. Haze: A thick mist in the air that makes it hard to see. Mist: A thick cloud of tiny water drops in the air. Smog: A type of air pollution that combines smoke and fog.

Which is more common: Fog, Haze, Mist, and Smog?

Fog is the most common in everyday English.

Can you show an example of each?

Fog: The fog rolled in quickly, making the road almost invisible. Haze: The view was limited due to the morning haze over the hills. Mist: The mist rolled in from the sea, creating an eerie atmosphere. Smog: The city was covered in smog, making it hard to breathe.

Can I use Fog, Haze, Mist, and Smog interchangeably?

Not always. Fog, Haze, Mist, and Smog are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.

Related comparisons