If you’ve ever booked a flight from the US or Canada to Europe, you might have noticed that most of your options are redeye flights that leave North America at night and arrive in Europe in the morning.

Ever wonder why that might be? If you’re like me, you probably have.

Being the curious sort, and a little bit of an Avgeek, I decided to get an answer once and for all.

Here are some of the reasons why most flights to Europe leave the US at night!

Time zone change

Europe is generally between 5 and 9 hours ahead of US time zones. Most flights from the US to Europe take between 7 and 12 hours.

This means, if your flight departs the US in the evening, you’ll arrive in Europe in the morning.

Let’s look at a couple of examples.

Scenario 1: You leave the east coast of the US at 8pm and it’s an 8-hour flight to your destination in Europe. You’ll arrive in Europe at 4am US eastern time, but at 9am or 10am European time.

Scenario 2: You leave the east coast of the US at 9am and it’s an 8-hour flight to your destination in Europe. You’ll arrive in Europe at 5pm US eastern time, but at 10pm or 11pm European time.

Why would Scenario 1 be preferable over Scenario 2? Keep reading to find out!

Traveler preference

Traveler demand indicates that many, if not most, people would prefer to leave the US or Canada in the evening and arrive in Europe in the morning.

Many people find night flights to Europe a more efficient use of time. An overnight flight means you can finish want you need to do in the US during the day (whether that be working or last-minute packing), head to the airport in the late afternoon or evening, sleep on your flight, and boom! You wake up in Europe, ready to go!

This is especially true for business travelers, who, for many airlines, are more profitable than vacationers. Business travelers tend to prefer the overnight flight, as it allows them not to waste a day. They can put in a full day of work in the US, hop on the red-eye flight, and arrive the next day in Europe in time to meet with European colleagues.

And that point about not wasting a day? That can be very attractive for leisure travelers as well. For some people, it feels like they get an extra day of vacation, putting in a full day of sightseeing as soon as they arrive. For others, it means preserving vacation time at work since they don’t have to an extra day off just to travel. Instead, they work a full day, then head to the airport in the evening.

Another reason that all travelers can benefit from? There are many more options to get to your hotel if you arrive in the morning than if you arrive late at night.

This is especially true if you plan on taking public transportation, which often has limited overnight hours, or sometimes doesn’t even operate late at night. The London tube, for example, doesn’t run between midnight and 5am.

Connecting flights to other parts of the world

When looking for a flight, you might have noticed that there isn’t a non-stop flight from your home city to your destination. So to get to where you want to go, you’ll need to connect.

Arriving in the morning in Europe means you’ll have lots of time, or at least lots more options, to catch a connecting flight. That’s true whether you’re going elsewhere in Europe or onward to other parts of the world. Many people heading to Africa, for example, must connect in Europe since there are not a lot of direct flights from the US to Africa.

No matter where someone is connecting to, a morning arrival in Europe increases the likelihood of catching the connecting flight the same day – instead of having to wait overnight and add yet another day to their travel itinerary.

Airline operational efficiency

Many flights to and from the US, especially for US-based carriers, are “turns,” meaning the plane lands, offloads, then turns around to head back to its starting airport.

Airlines like high usage of their planes; it’s more efficient and in turn (pun intended) makes the airlines more money.

If a plane leaves the US at night and arrives in the morning, it can then return to the US a few hours later. The airline can get two flights, with two sets of paying passengers, on the same day.

Conversely, if the plane departed the US in the morning and arrived in Europe in the evening, it would have to remain at the airport overnight and can only fly back to the US the next day. So the airline would only get one flight (and one set of paying passengers) for the day, essentially cutting their revenue potential.

Airport time slots

You might have asked yourself why the hypothetical day flight from the US would mean that the plane would have to stay in Europe overnight. Why couldn’t it just fly back as a night flight back to the US?

This is because airlines are only accorded certain slots at airports. To reduce noise pollution, many airports only allow limited slots at night; far more daytime slots are available. Airlines must therefore schedule their flights to arrive during the day.

Weather/Atmospheric conditions

Flying at night means you’re less likely to run into bad weather. When you’re on a plane, that means a smoother flight.

It could also mean better efficiency for the plane. Air is less dense at night, meaning planes run more efficiently; in other words, more cheaply for the airlines.

Now you know! If you want to read more about the history of flight, check out my article on the topic here!