When to Book Flights for the Best Price

There’s one question every traveler asks at some point: when is the cheapest time to book?

The honest answer: it depends. But not on luck — on a few concrete factors that you can actually know.

The ground rules by route type

Short-haul Europe

Optimal window: 6–10 weeks before departure

European low-cost carriers like Ryanair, easyJet, and Wizz Air fill their planes fast. Booking 3 months out often costs the same as 3 weeks out — simply because demand is spread fairly evenly.

The sweet spot is 6–8 weeks out. That’s when enough cheap seats are still available, but prices haven’t yet climbed. The price gap between this window and last-minute booking can be 30–50% on popular routes like Frankfurt–Barcelona or London–Madrid.

Exception: school holidays. Easter and summer flights fill up early. If you want to fly over Christmas, book in September at the latest.

Transatlantic (USA, Canada, Caribbean)

Optimal window: 3–5 months before departure

Transatlantic routes are booked well in advance. Airlines open booking windows up to 11 months ahead — and the cheapest seats disappear within the first few weeks.

If you’re thinking about a spontaneous trip to New York: last-minute rarely works here. In fact, last-minute transatlantic bookings are often significantly more expensive than the average price.

Asia (Japan, Thailand, Singapore, Bali)

Optimal window: 4–6 months before departure

Asia flights are long and comparatively expensive. Direct flights to Tokyo or Bangkok range from €600 to €1,500, depending on timing, airline, and season.

Airlines like Lufthansa, Singapore Airlines, or ANA open their most attractive fares early. Booking early gets you better prices and more seat choice.

Important: check visa requirements well in advance. Japan and Thailand require no visa for EU citizens on short stays; other destinations do.

Middle East and Africa

Optimal window: 2–4 months before departure

Price variance is highest here. Dubai flights can range from €300 to €900 depending on airline, booking timing, and season. Market-watching and price alerts pay off here especially.

What else affects the price

Day of the week for booking Booking on Tuesday or Wednesday tends to be slightly cheaper. For more tricks, see our guide 7 Tricks to Find Cheaper Flights.

Day of the week for departure Friday and Sunday are expensive. Tuesday and Wednesday are cheap. On busy routes, the difference can be 20–40%.

Time of departure Early morning (before 7 AM) and late evening (after 9 PM) flights are less popular — and therefore cheaper. Bonus: these flights have statistically fewer delays.

Seasonality Every destination has a high season. Mallorca in August costs three times as much as Mallorca in October — and October is often nicer. Avoiding peak holiday periods can save you serious money.

Understanding the pricing system

Airlines use dynamic pricing systems. Every ticket belongs to a booking class. The cheapest classes have limited allocations. When one allocation sells out, the price jumps to the next tier.

That means prices don’t rise linearly — they jump. A flight that cost €180 yesterday might cost €240 today because the cheap booking class sold out. This explains why prices can seem to fluctuate randomly.

Last-minute: when it works

Last-minute makes sense under very specific conditions:

The route has many competitors (e.g. London–Barcelona with multiple low-cost carriers)
You’re truly flexible — including with the destination
You’re traveling solo, without hotel bookings, without fixed plans

For family trips, pre-booked hotels, or long-haul: forget last-minute. The potential price advantage is outweighed by risk and limited choice.

Using price alerts effectively

Google Flights, Kayak, and Skyscanner all offer price alerts. Enter a route and target price — and get an email when the price drops.

This prevents impulse-buying an expensive flight just because you happened to check. Set it, forget it, and book when the price is right.

The short summary: book short-haul 6–10 weeks out, long-haul 3–5 months out. Avoid Friday and Sunday departures. Be flexible — a single free travel day can be worth a hundred euros.

Zercy factors all of this in automatically. Type “Tokyo in November” and Zercy calculates which days and airports offer the best options — without you having to compare manually.

Frequently Asked Questions

How many weeks in advance are flights cheapest?

For short-haul in Europe: 6–8 weeks before departure. For long-haul to North America: 3–5 months. For Asia: 4–6 months. Booking outside these windows usually costs more — earlier due to higher starting prices, later due to rising demand.

Why do flight prices fluctuate — and seem to rise after you’ve looked once?

Sometimes. Airlines use dynamic pricing that responds to overall demand. Whether individual searches raise prices is not proven — but possible. Searching in incognito mode doesn’t hurt. The bigger lever is comparing different platforms and setting price alerts.

When are early-bird prices actually worth booking?

Not always. Airlines open their cheapest allocations early, then raise prices, and sometimes drop them again just before departure if seats remain. The sweet spot is usually neither the first nor the last day — but the middle booking window.

When should you use price alerts versus just booking early?

If you have a flexible schedule and plenty of lead time: price alerts work well. If the date is fixed (holiday, event, wedding), book early within the optimal window rather than waiting for a drop that might not come.

When Should You Book Flights? The Optimal Timing