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The cheapest day to book and to fly

Time it right for the lowest air fares to France, Portugal, Spain, Thailand, USA and other destinations

The best time to book flights from the UK is six months before departure, on average, according to research by flight comparison site Skyscanner.

For some destinations you need to book even earlier to get the cheapest prices. A new tool launched by Skyscanner calculates that flights to New York are cheapest almost a year in advance (see table below). Prices for August trips to Barcelona also bottomed out 12 months before travel, based on data from 2022.

The good news is that for some destinations you don’t need to be so organised. May holidays to Rome were cheapest around three months before – meaning you could bag a bargain in the next few weeks.

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What day should you fly?

Typically, Tuesday is the cheapest day to fly and Saturday is the most expensive, but this can vary. When we used the tool to look at a December holiday to Bangkok, Tuesday was actually the most expensive day. Monday was the cheapest.

Airlines use ‘dynamic pricing’, meaning that fares rise and fall according to the number of tickets sold and the time left before departure. The cheapest flight one day might not be such a good deal the next.

That’s why it’s a good idea to start tracking prices well ahead of your departure date. You can also set up a flight alert with Skyscanner or other comparison sites including Kayak and Google Flights, so you receive an email if the price of the flight you’re looking at changes.

You can see our reviews of the best and worst flight comparison sites here.

How the ‘when to book’ tool works

The site lets you choose your departure airport, from a list of 77 airports around the world, the month you want to fly, and where you want to go.

It then tells you how long before your trip to book, the best day to fly and how much you’ll save by booking then, in comparison with the average price.

Destinations are limited. We were only shown 14 when we set our departure city as London, but Skyscanner says that the site is designed to demonstrate ‘the benefit of shopping around’. It includes 10 different countries and 777 cities overall.

You can find out more about Skyscanner's tool here.

When to book flights to Bangkok, Barcelona, Dubai, New York and Rome

CityWhen to book for a May holidayWhen to book for an August holidayWhen to book for a December holiday
Barcelona22 weeks before52 weeks before23 weeks before
Bangkok19 weeks before28 weeks before49 weeks before
Dubai50 weeks before33 weeks before51 weeks before
New York51 weeks before51 weeks before46 weeks before
Rome12 weeks before24 weeks before35 weeks before

How to get cheap flights

Another way to ensure that you get a good deal is to be flexible in your destination – as well as the date of your flight. Skyscanner allows you to choose ‘everywhere’ as your destination, so you can see the cheapest flights available.

See more tips on how to save money on flights here.