National Weather Service United States Department of Commerce

Flying in fog is quite challenging, even for the most experienced of pilots. For pilots that are not as skilled, fog is an extremely dangerous and potentially deadly hazard. Each year, around 440 people are killed due to weather-related aviation accidents including the conditions of low visibilities and ceilings. If you are planning a flight and it’s foggy or will potentially be fog, follow these safety guidlines:

  • Get the latest forecasts, advisories and observations to help make your flight safe from NOAA's Aviation Weather Center.
  • Consider changing your plans to avoid flying in fog.
  • It is imperative that you specifically follow the Federal Aviation Administration mandated guidelines and flight rules for the specific flight category based on visibility and ceiling height. The ability to operate in fog depends on three factors: the capability of the pilot (i.e., instrument rating), the capability of the aircraft, and the capability of the airport. Flight categories are:
    • Instrument Flight Rules (IFR) or Instrument Meteorological Conditions (IMC): Ceilings below 1,000 feet AGL and/or visibility less than 3 miles.
    • Marginal Visual Flight Rules (MVFR): Ceilings, 1,000 to 3,000 feet AGL and/or visibility 3 to 5 miles.                        
    • Visual Flight Rules (VFR) or Meteorological Conditions (VMC), MVFR is considered VMC: Ceilings: greater than 3,000 feet AGL and visibility greater than 5 miles
  • If you must fly, it is important to know the layout of the airport you are departing from or arriving to, including the length and orientation of the runway, as well as the entire flying area.
  • Be aware of the potential for freezing fog. If temperatures are at or below freezing and fog is present, a thin layer of ice may form on the plane.
  • Always file a flight plan.

Take the free training courses offered by the COMET program, sponsored in part by NOAA. These classes can help you learn more about flying in fog and how other weather phenomena impacts aviation.