SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/ifr-fg-visibility

In a METAR, FG means fog restricting visibility to less than what?

Less than 5/8 statute mile.

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  1. 5/8 statute mile ✔
  2. 1 statute mile
  3. 3 statute miles

Why: FG is reported when fog reduces visibility to less than 5/8 statute mile. From 5/8 to less than 7 statute miles, mist (BR) or haze (HZ) is reported instead, depending on the temperature and dewpoint spread.

Huh, didn't know that: Freezing fog, coded FZFG, is reported when the temperature is below 0 degrees C.

The dad joke
What type of cloud is so lazy, because it will never get up? Fog!
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References

Answer: 5/8 statute mile. FG is reported when fog reduces visibility to less than 5/8 statute mile. From 5/8 to less than 7 statute miles, mist (BR) or haze (HZ) is reported instead, depending on the temperature and dewpoint spread.

  1. FAA Aviation Weather Handbook (FAA-H-8083-28B) www.faa.gov/sites/faa.gov/files/FAA-H-8083-28B.pdf
    FG is reported when visibility is less than 5/8 SM.
    Checked 2026-10-11.
  2. FAA Aviation Weather Handbook (FAA-H-8083-28B) www.faa.gov/sites/faa.gov/files/FAA-H-8083-28B.pdf
    Freezing fog (FZFG) is reported when temperature is below 0°C.
    Checked 2026-10-11.
  3. FAA Aviation Weather Handbook (FAA-H-8083-28B) www.faa.gov/sites/faa.gov/files/FAA-H-8083-28B.pdf
    BR or HZ is reported for visibilities from 5/8 SM to less than 7 SM,
    Checked 2026-10-11.
  4. FAA Aviation Weather Handbook (FAA-H-8083-28B) www.faa.gov/sites/faa.gov/files/FAA-H-8083-28B.pdf
    Obstructions to vision: fog (FG), mist (BR), and haze (HZ).
    Checked 2026-10-11.

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