What causes most flight delays

Flight delays happen for reasons that fall into two groups: things the airline controls, and things it doesn't. Weather is the biggest uncontrollable cause—thunderstorms, fog, snow, and high winds can ground planes or force them to circle before landing. Air traffic control congestion, especially around major hubs during peak hours, also creates delays that no single airline can fix.

On the airline side, mechanical problems are common. An engine issue, a broken lavatory, a faulty door latch, or a malfunctioning navigation system can all ground a plane until it's fixed. Crew scheduling problems—a pilot or flight attendant running late from a previous flight, or not enough crew available—also cause delays. Baggage handling delays, catering issues, and boarding problems add time too, though usually in smaller increments.

Staffing shortages at airports have grown since 2020. When ground crews, gate agents, or security screeners are understaffed, planes sit at the gate longer waiting for a crew to push back, or flights back up because security lines move slowly. This is different from weather or mechanical delays—it's a structural problem that persists across multiple days.

Key Takeaways

  • Weather and air traffic control delays are outside the airline's control, while mechanical problems and crew scheduling are the airline's responsibility.
  • A delay of 15 minutes on the ground often means a 30-minute or longer arrival delay because planes must make up time in the air or wait for a gate.
  • If your flight is delayed more than three hours and you're flying within, to, or from the European Union, you may be may have access to to compensation under EU261 rules.
  • The airline must rebook you on the next available flight at no cost if they cancel your flight, but delays do not automatically trigger rebooking.
  • Checking your airline's app or website gives you real-time delay information faster than calling customer service.

How delays compound through the day

A single delay early in the morning can ripple through an entire airline's schedule. If a plane is supposed to fly from New York to Boston at 7 a.m. and doesn't leave until 8:30 a.m., that same plane is now scheduled to leave Boston for Miami at 10 a.m.—but it won't arrive in Boston until 9:45 a.m. The Miami flight gets pushed back. Passengers booked on the Miami flight miss connections in Miami. By afternoon, the airline is managing dozens of delayed flights across multiple cities, all stemming from one early problem.

This is why a delay of 30 minutes on the ground often becomes a 60-minute or longer arrival delay. The plane loses time sitting, then must wait for a gate at the destination airport because other planes are still parked there. Gate availability is a real constraint at busy airports during peak hours.

Airlines try to prevent this by building buffer time into schedules, but that buffer fills up quickly once delays start. Planes flying cross-country have more buffer than short regional flights, so a delay on a short hop causes more downstream problems than the same delay on a long flight.

What your airline must tell you about delays

U.S. airlines are required to inform you of a delay as soon as they know about it. In practice, this means checking your airline's app or website—that's where the information appears first. The airline will also send a text or email if you signed up for notifications, though these sometimes arrive after the app has already been updated.

The airline does not have to tell you the reason for a delay in real time, though many do. They must provide a reason if you ask, but the reason may be vague: "mechanical issue," "crew scheduling," or "weather." You won't always get specifics about what broke or why the crew was late.

If a delay stretches past two hours, the airline must provide food and water if the delay is their responsibility (not weather or air traffic control). They must also offer phone calls or emails. If the delay will be overnight, they must provide a hotel room and ground transportation. These rules explore only if the delay is the airline's fault—weather delays don't trigger these requirements.

When you're may have access to to money because of a delay

In the United States, airlines are not required to pay you money for delays, even long ones. This is different from cancellations, where the airline must rebook you for free. A three-hour delay does not automatically mean compensation.

However, if you are flying within, to, or from the European Union, you may be may have access to to compensation under EU261 rules. The amount depends on flight distance and delay length. A delay of three hours or more on arrival can mean €250 to €600 per passenger, depending on whether the flight was short-haul (under 1,500 km) or long-haul (over 3,500 km). The airline must pay this unless the delay was caused by extraordinary circumstances—severe weather, a security threat, or an air traffic control strike—that the airline could not have prevented.

Some credit card companies offer trip delay reimbursement if you booked the flight with their card. Check your card's benefits guide to see if this applies to you. You'll need to document the delay and submit a claim.

What to do if your flight is delayed

First, check your airline's app or website for the current status. This is faster than calling. The app will show you the new departure time, gate number (if assigned), and sometimes the reason for the delay.

If the delay is more than two hours and the airline is responsible (not weather), ask the gate agent for food and water vouchers or reimbursement. Keep your receipts. If the delay will be overnight, ask about hotel and transportation. The airline must provide these, though you may need to ask—they don't always volunteer.

If you're going to miss a connection, tell the gate agent before you land. They can rebook you on the next flight to your final destination at no cost. If you don't tell them and you miss the connection, you'll have to rebook yourself, and the airline may charge you for a new ticket.

If the delay is weather-related and your flight is eventually cancelled, the airline must rebook you on the next available flight at no cost. If no flights are available that day, they must rebook you for the next day. You can also choose to cancel and get a refund of your ticket price.

How to know if a delay is weather or the airline's fault

The airline will tell you the delay is weather-related if that's the cause. You can verify this by checking weather reports for the airport where your plane is or where it's headed. If there's a thunderstorm, heavy snow, or fog at that airport, the delay is likely weather.

If the airline says the delay is mechanical or crew-related, that's the airline's responsibility. If they say "air traffic control delay," that's outside their control. You can check the FAA's website for air traffic delays at major airports, though the information updates slowly.

The distinction matters because weather delays don't trigger food and water requirements, and they don't may have access to for EU261 compensation. Airline-caused delays do. If you're unsure, ask the gate agent what caused the delay and whether it's weather-related.

Delays versus cancellations—what's different

A delay means your flight will eventually leave and arrive, just later than scheduled. A cancellation means the flight is not operating at all. The airline's obligations are different for each.

For a delay, the airline must provide food, water, and hotel (if overnight) only if the delay is their fault. They don't have to rebook you on another airline or refund your ticket. You arrive late, but you arrive.

For a cancellation, the airline must rebook you on the next available flight at no cost, even if it's on a different airline. If no flights are available that day, they must rebook you for the next day and provide a hotel. You can also refuse the rebooked flight and get a full refund. Cancellations are more disruptive, but the airline's obligations are clearer and more generous.

Frequently Asked Questions

Can I get off the plane if we're delayed on the tarmac?

The FAA requires airlines to let passengers off a plane that's been sitting on the tarmac for three hours (domestic flights) or four hours (international flights) without a mechanical reason to stay. If the delay is weather or air traffic control, the airline can keep you on the plane longer. Ask a flight attendant if the three-hour or four-hour limit applies to your situation.

What if my delay causes me to miss a connection?

Tell the gate agent before you land. They will rebook you on the next flight to your final destination at no cost. If you don't tell them and you miss the connection, you'll have to rebook yourself, and the airline may charge you for a new ticket unless you can prove the delay was their fault.

Do I get a refund if my flight is delayed?

No. A delay does not may have access to you to a refund in the United States. You can only get a refund if the flight is cancelled and you choose not to rebook. If you're flying to or from the EU, you may be may have access to to compensation money (not a refund) if the delay is three hours or more and the airline is responsible.

How long do airlines usually delay before cancelling?

There's no set rule. Airlines will delay as long as they think the problem can be fixed—a mechanical issue might take two hours, or it might take six. If they decide the problem can't be fixed in time, they cancel. Weather delays can last hours while the airline waits for conditions to improve. Check your airline's app for updates every 30 minutes.

Can I change my flight if it's delayed?

You can ask the airline to rebook you on an earlier flight if one is available, but they're not required to do so unless your flight is cancelled. Some airlines will move you to an earlier flight at no cost if seats are available, especially if the delay is their fault. It never hurts to ask the gate agent.