Lonely Planet Writer

There may be no “best day” to book, but there are tricks to saving on flights

Every so often research comes out telling travellers the best day to book a flight. But with constant fluctuations in prices – and so much depending on your destination – there are no hard and fast rules. Thankfully, there’s always some advice that helps, and Kayak’s latest research can offer a push in the right direction when it comes to helping Americans get the best price on travel.

Surfers carrying surf board, walking along beach in San Diego.
Learn how to save money on flights so you can head to California. Image by ©Corey Jenkins/Getty Images

How to get the best deal on flights

According to Kayak, plan ahead. Their research shows that travellers find the best deals on domestic flights when booking at least two to four weeks in advance. When it comes to both international and domestic flights, Friday is the cheapest day to fly out compared to the rest of the week. Since the most expensive day is Monday, you can actually save about $100 by starting your trip Friday, according to Kayak. Monday is also the cheapest day to head home, coming in at about $100 cheaper than the most expensive day, Thursday.

The Manhattan skyline at sunset in New York City.
The Manhattan skyline at sunset in New York City. Image by pisaphotography/Shutterstock

The most and least expensive days to travel in the US

Since demand has an obvious effect on flight prices, there are just some days that will always be more expensive than others. For winter travel, between 21 December and 20 March, the day after Christmas is the priciest for domestic travel in the US. Prices also go up in early January around the Martin Luther King Jr Day holiday, but drop for the last week of the month. Since summer is one of the most popular times to take a holiday in the US, airfare will peak at the end of July, with 31 July being the most expensive in 2016. If you can wait until mid- to late-September after Labor Day, prices will be more favourable. In the fall, between 22 September and 21 December, prices will spike on the Sunday after Thanksgiving, so make sure you plan ahead.

The Eiffel Tower in Paris. Image: ESB Professional/Shutterstock

The most and least expensive days for international travel

In 2016, Christmas was on a Sunday, which meant many travellers took advantage of turning a longer holiday into a trip aboard. The most expensive day to travel that year was 21 December, and with Christmas on a Monday this year, prices are expected to rise for travel on the Wednesday and Thursday before the holiday. If you can wait a bit longer, Kayak data shows that a good deal is more likely in late February and early March. In the fall, waiting until September is your best bet – with Thursday, 15 September coming in as the cheapest day for travel. As Christmas approaches, the most expensive time to fly internationally is the weekend before Christmas.