The short answer
If you want the lowest fares in 2026, look at January, February, September, and October first. Those are the months when demand drops after a busy season ends, and airlines lower prices to fill seats.
January and February follow the Christmas and New Year rush. People have spent their holiday budgets, the weather is cold in much of the northern hemisphere, and fewer people are booking leisure trips. September and October work the same way after summer: schools are back, family holidays are over, and the autumn shoulder season begins.
That does not mean every flight in those months is cheap, or that other months never have good fares. The route, the destination, and how far ahead you book all matter. But if your dates are flexible, starting with those four months gives you the best odds.
January and February: the post-holiday dip
January is widely regarded as the cheapest month to fly for domestic trips in the United States, and February runs close behind. The pattern is simple. Demand falls sharply after New Year’s Day, and it stays low until spring break and Easter pull it back up.
There are exceptions to watch. The first few days of January are still busy with people returning from holiday trips, so fares usually settle a few days after New Year’s Day. In the US, the long weekend around Presidents’ Day in mid-February can also push prices up for a few days.
For Europe, the low-fare window is longer. Fares between November and March are generally lower than in summer, as long as you avoid the Christmas and New Year period itself. A city break to London, Paris, or Rome in late January or February can feel like a different trip — fewer crowds, shorter queues, and often much lower airfares — though the weather is colder and daylight is shorter.
If you can travel in these months, pack for the season and enjoy the quieter side of popular places.
September and October: the autumn sweet spot
September and October are the second-best window, and for many travellers they are the better one. The weather is still mild in many destinations, but the summer crowds have gone home.
In Europe, April to May and September to October are the classic shoulder seasons: good weather, thinner crowds, and fares often well below peak summer levels. September is especially strong for long-haul flights, as summer demand fades before business travel fully picks up again.
October is often the pick of the two for domestic trips in the US, once the summer rush has fully passed. It is also a good month for city trips, when walking around is pleasant and attractions are easier to visit.
The trade-off is small. Some beach destinations start to cool down, and a few seasonal attractions close in October. For most city and cultural trips, though, autumn is hard to beat.
The months to avoid if price matters
June, July, and December are consistently the most expensive months to fly. Summer is peak family-holiday season, and December brings Christmas and New Year travel, when almost everyone wants to fly on the same few days.
That does not mean you should never fly in those months. If you must travel in July or over Christmas, the booking advice below matters even more: book earlier, be flexible on the day you fly, and set a fare alert as soon as you know your dates.
Spring break, Easter, and school half-term weeks can also spike prices on popular routes, even in otherwise cheap months. If your trip overlaps with a school holiday in your destination, expect higher fares.
When to book: the window that works
The cheapest month to travel and the cheapest time to book are two different things. Getting both right is what saves real money.
For domestic flights, the sweet spot is generally one to three months before departure. Booking data from Google Flights and CheapAir’s annual airfare study points to the lowest fares clustering around 30 to 45 days out for many US routes. Book much earlier than that and you may pay the initial release price, before airlines start competing. Book much later and the cheapest seats are gone.
For international flights, give yourself more time: two to eight months before departure is the usual guidance, with long-haul trips to Europe or Asia often cheapest around two to six months out. For peak summer dates, start tracking fares seven to eight months ahead, even if you do not buy straight away.
The pattern to avoid is waiting until the last two weeks. Fares usually rise, not fall, as departure nears. CheapAir’s study found domestic fares averaging well above the cheapest window in the final two weeks before takeoff, and higher still in the final few days. Last-minute deals exist, but they are the exception, not the rule.
The cheapest days to fly
The day of the week matters too. Tuesday, Wednesday, and Saturday departures tend to be the cheapest, while Sunday is usually the most expensive day to fly. Expedia’s 2026 data found flying domestically on a Tuesday noticeably cheaper than flying on a Sunday.
The same logic applies to the day you book, though the effect is smaller. Some reports find Sunday the cheapest day to book international fares, while others point to Friday. Do not build your whole plan around the booking day — the travel dates and how far ahead you book matter far more.
If you can, fly midweek and avoid Friday evenings and Sunday afternoons, when business and weekend travellers fill the planes.
How to actually catch a low fare
Knowing the cheapest months is only half the job. These habits turn the knowledge into a booking:
Be flexible by a day or two. Shifting a departure from Sunday to Tuesday, or a return from Monday to Wednesday, can change the fare by more than shifting the whole trip by a month. Use a flexible-dates search and compare the whole week.
Set a fare alert early. As soon as you know roughly where and when you want to go, set an alert on Google Flights or your usual booking site. You will see the price pattern for your route, and you will know when a dip is real rather than a guess.
Compare nearby airports. A smaller airport an hour away, or flying into a different city and taking a train, can be much cheaper than the obvious airport. Check the total cost, including the transfer, before deciding.
Travel light when it helps. On short trips, a fare that looks cheap can stop being cheap once baggage fees are added. If you can manage with a carry-on, compare the all-in price, not just the headline fare.
Book the return at the same time. One-way fares are not always half of a return fare. Price the round trip before you book two singles.
For more on what actually happens in the air, see How Fast Do Planes Go? — and if you like slow travel once you land, the Glamping Economy is a good reminder that the cheapest part of a trip is often the stay, not the flight.
A simple plan for 2026
If you are planning a trip in 2026 and want the lowest fares, here is the simplest version of everything above:
- Aim to travel in January, February, September, or October if you can.
- Book domestic flights one to three months ahead, and international flights two to eight months ahead.
- Fly on a Tuesday, Wednesday, or Saturday where possible.
- Set a fare alert as soon as you know your dates, and book when the price dips into your budget — do not wait for a perfect fare that may never come.
No calendar guarantees a cheap flight. But travelling in a quiet month, booking in the right window, and flying midweek stack the odds in your favour — and that is usually enough to make a real difference to the cost of a trip.