Can Flights Land in Fog? | What Determines The Go/No-Go

Airliners can land in thick fog when runway visibility readings and certified aircraft systems meet the published minimums.

If you’re asking, “Can Flights Land in Fog?” you’re already thinking like an airline dispatcher. Fog can make an airport look shut down, yet many flights still arrive on schedule. The difference comes down to measured visibility on the runway, the type of approach available, and what the aircraft and crew are approved to do.

Below you’ll learn what the numbers mean, why delays pile up even when planes still touch down, and how to read a fog day like a frequent flyer.

Can Flights Land in Fog? When It’s Allowed

Yes, flights can land in fog. The limit comes from the approach chart for a specific runway. Each approach lists a decision height and a required visibility value. If the measured visibility is below that value, pilots can’t continue the approach to a landing.

Three things must line up at the same time: the runway must have the right approach and lighting, the aircraft must be equipped and working properly, and the airline crew must be approved for that level of low-visibility operation. If any one of those pieces isn’t in place, the flight may try a higher-minimum approach, hold to wait for improvement, or divert.

There’s also a timing piece. Conditions can meet minimums when the airplane starts the approach and then drop a few minutes later. That’s why you can hear “we’ll give it one try” even at airports that handle fog well.

How Runway Visual Range Shapes The Call

Airports don’t rely on a single “overall visibility” number. They also use runway visual range (RVR), a measurement taken along the runway that reflects what a pilot should be able to see during touchdown and rollout. The FAA’s page on Runway Visual Range (RVR) describes how sensors can report visibility at points like touchdown, midpoint, and rollout.

That runway-by-runway detail is why fog can look “the same” from the terminal and still produce different outcomes. One end of the runway may be usable while the rollout end drops below the minimums, which is a deal-breaker for a safe landing.

RVR also explains the strange feeling of “we’re holding while the airport is right there.” A pilot may be able to see the airport area from above the fog, yet still be unable to meet the runway visibility requirement down low.

How Instruments And Automation Handle Fog

Fog landings are built around instrument approaches. The Instrument Landing System (ILS) is the best-known tool because it gives precise lateral and vertical guidance down to the runway. Many airliners also fly other published approaches, yet ILS is still the common path to the lowest visibility operations at major airports.

In low visibility, crews may keep the autopilot engaged deep into the approach. Some aircraft and runways support autoland, where the system flies the final segment and manages the flare with minimal outside view. After touchdown, centerline lights, runway edge lights, and braking systems help keep the airplane aligned as it slows.

Airplanes and runways are certified together in a practical sense. The runway must provide the right signals and lighting, and the aircraft must have redundancy that matches the operation. If a required component fails—an autopilot channel, a radio receiver, a warning system—the crew may still continue at a higher category, or they may need to discontinue and go around.

What “CAT I, CAT II, CAT III” Means In Plain Terms

Category labels bundle together runway equipment, aircraft capability, and crew approvals. Higher categories allow operations in lower visibility, but only on runways qualified for that category and only for operators with the right authorizations. The FAA’s Category I/II/III ILS information page explains that qualified runways are published as Category I, II, or III for operators who can use them.

Why Delays Stack Up Even When Planes Still Land

Fog doesn’t have to stop arrivals to slow an airport. The runway can stay open while the arrival rate drops, and that’s where the timetable starts to bend.

More Space Between Arrivals

Controllers increase spacing so there’s room for a missed approach and so each aircraft has time to clear the runway. Fewer arrivals fit into each hour, so inbound flights may hold, and outbound flights may wait for gates.

Slower Taxi And Fewer Crossings

Taxi speeds drop, runway crossings take longer, and airports may restrict certain routes during low-visibility operations. Those extra minutes ripple across the whole field.

One “Best” Runway Gets Overloaded

When one runway has the lowest minimums, the airport may funnel more traffic to it. That can create a single bottleneck for both landings and departures.

Then there’s the human side of the schedule. When flights land late, gates fill up, crews hit duty-time limits, and aircraft rotations break. A foggy morning in one city can turn into afternoon delays across the map.

Why Two Airports In The Same Fog Can Perform Differently

Fog days reveal the difference between “weather” and “capability.” Two nearby airports can report similar conditions, yet one keeps moving while the other slows sharply.

• Lighting package. Better approach and runway lighting supports lower minimums.
• Approach options. A working ILS (and backups) offers more ways to get in when visibility is low.
• RVR sensor availability. If sensors are out of service, the runway may revert to higher minimums.
• Traffic pressure. Busy arrival banks magnify any drop in hourly capacity.

Why Flights Divert On Foggy Days

Even at a runway that supports low-visibility approaches, a flight can still divert. The margins can be tight, and the decision is driven by what’s happening right then, not what happened earlier.

Common diversion triggers include:

• Visibility drops below minimums. Fog can thicken fast, and the runway may fall under the required RVR.
• Equipment restrictions. An ILS outage, lighting issue, or missing RVR report can raise minimums.
• Wind and runway condition. Crosswinds plus wet pavement can tighten stopping margins.
• Fuel limits after holding. If holding time eats into reserves, crews must head to the alternate.
• Aircraft or crew limits. Not all aircraft are set up for the lowest category, and not all crews are cleared for it that day.

What Must Be In Place	How It Affects A Fog Landing	What You’ll Often See If It’s Missing
Runway RVR readings	Confirms usable visibility during touchdown and rollout	Higher minimums, holding, or paused arrivals
Published minimums for the approach	Sets the visibility and decision height the crew must meet	Go-around at the decision point or an early diversion
Working ILS (or other precision guidance)	Keeps the aircraft on a stable path to the runway	Only higher-minimum approaches available
Low-visibility runway lighting	Gives alignment cues when outside view is limited	Minimums rise and the runway handles fewer arrivals
Aircraft systems approved for the operation	Supports precise tracking and, on some flights, autoland	Lower category not usable on that aircraft tail
Crew authorization and currency	Allows the crew to fly the category used that day	Flight restricted to higher minimums
Safe spacing and runway occupancy margin	Reduces runway conflicts when visibility is low	Longer holds, gate waits, and departure queues
Fuel plan with a legal alternate	Gives a safe out if conditions drop mid-stream	Earlier diversion to protect reserves

What A Fog Landing Feels Like On Board

Most of the time, it’s calm. You may notice a longer final approach, a steady descent that feels “on rails,” and then a sudden pop of runway lights near the end. After touchdown, the rollout can feel more deliberate as the crew tracks centerline lights and exits at a taxiway they can identify clearly.

A go-around is also normal on fog days. It can happen even after a smooth approach if visibility dips under minimums at the last moment, if traffic is still clearing the runway, or if the crew doesn’t get the visual cues they need at the decision point.

Moves That Help Travelers On Fog Days

Fog is common in many U.S. regions, especially around sunrise. A few planning choices can cut stress and reduce the odds of a domino-effect delay.

Choose A Later Departure When You Have Flexibility

Morning fog often eases later in the day. A midday flight can land after the airport’s arrival rate has returned.

Favor Nonstops When The Schedule Is Tight

Connections multiply risk. One fog delay can turn into a missed connection and a long rebooking line.

Track Your Inbound Aircraft

If your plane is arriving from a fog-affected hub, your departure may slip before boarding. Airline apps often show where the aircraft is and whether it’s holding or diverted.

Pack For A Delay Or A Short Diversion

Keep chargers, a snack, and time-sensitive items in your carry-on. If the flight diverts, you may spend extra time on the ground before continuing, and you’ll be glad you’re not waiting on a checked bag.

If your trip is time-sensitive, check the airline’s later flights on the same route before you leave home. When rebooking opens, having a Plan B in mind makes the whole process faster.

Signal In The App	What It Often Points To	What You Can Do
“Inbound aircraft delayed”	Late arrival from another foggy airport	Leave later for the airport; watch for gate changes
“Awaiting ATC clearance”	Traffic management spacing due to low visibility	Expect a late push; keep food and water handy
“Holding for weather”	Arrival rate reduced; runway near minimums	Check alternate flights in the app before lines form
“Diverted”	Runway dropped below minimums or a runway restriction	Wait for the airline’s plan; keep notifications on
“Crew legality” or “Crew scheduling”	Delay chain pushed crew duty limits	Look for rebooking options as soon as they appear
Gate hold after landing	Gate not open yet due to arrival backlog	If you’re connecting, alert a flight attendant early

A Practical Checklist Before You Leave Home

• Check conditions at both your departure and arrival airports.
• Scan the inbound aircraft status in your airline app.
• Turn on push alerts for gates, delays, and rebooking.
• Keep must-have items in your carry-on, including meds and chargers.
• If you have a connection, note one or two backup flights.

Fog isn’t a blanket “no.” It’s a measured, runway-specific problem with clear limits. When RVR, runway equipment, and aircraft approvals line up, flights can land safely. When they don’t, delays and diversions protect safety—and that’s exactly the point.