Cheapest Times to Fly: Weekly Airfare Data for Every Month, Day & Booking Window

What Is the Cheapest Time of Year to Fly?

The cheapest time to travel depends on where you’re flying from and where you’re going, but clear patterns emerge when you look at millions of routes in aggregate. The chart below shows the average round-trip airfare by week of the year for all flights worldwide, in inflation-adjusted USD.

The cheapest time to fly is from the second week of January through the end of February, when post-holiday demand drops sharply. The next cheapest window runs from late August through mid-November, as summer travel winds down. During these off-peak weeks, the worldwide average round-trip fare drops to roughly $1,146–$1,265, compared to peak fares above $1,500.

December is the most expensive month overall, but that’s entirely driven by the final two weeks. Early December is actually quite affordable. Outside the holidays, June and July command the highest fares, with prices climbing toward the end of July and tapering off as Northern Hemisphere summer vacations end.

For travelers who prefer warm weather but want lower fares, there’s a sweet spot: mid-August through early October combines pleasant temperatures in many destinations with significantly lower ticket prices.

Why weekly data matters

Most airfare guides show monthly averages, which can be misleading. December looks uniformly expensive on a monthly chart, but the first two weeks are actually moderate. Similarly, May appears affordable overall, but Memorial Day week commands a premium. Our weekly granularity reveals these details so you can plan around the specific expensive weeks rather than writing off entire months.

The U.S. summer vacation season is a major price driver. School calendars vary by state, but somewhere in the country schools are out from May through the first week of September. You can see this clearly in the data: demand (and prices) rise as vacation season opens in late May and fall as it closes after Labor Day. Flexible travelers can find deals at the edges of these windows.

Which Day of the Week Is Cheapest to Fly?

Day-of-week pricing is remarkably consistent across destinations. While seasonal patterns differ by route, the same days tend to be cheaper almost everywhere.

Tuesdays and Wednesdays are cheapest for nearly every route in our dataset. Sundays, Fridays, and Saturdays are the most expensive.

On average, a Tuesday departure costs 80–90% of what the same flight costs on Sunday. That translates to roughly $59 in savings simply by shifting from Monday to Tuesday, or $124 by choosing Tuesday over Sunday. These differences are intentional: airlines price mid-week flights lower to fill planes more evenly across the week. Weekend staffing is more expensive, so carriers use pricing to nudge flexible travelers toward Tuesday and Wednesday departures.

How Far in Advance Should You Book a Flight?

All prices in our analysis assume booking at least 30 days before departure. Fares aren’t guaranteed—they shift constantly as airlines adjust capacity, manage maintenance schedules, and respond to demand. Fuel-price swings add another variable.

As a general rule, book at least four weeks before your travel date. The chart below shows how average fares increase as the departure date approaches.

Fares rise steeply inside the three-week window, reaching roughly 77% above the 30-day-advance price on the day of departure. The curve is gentle at first—you lose only about 2% between 40 and 30 days out—then accelerates sharply.

You may encounter advice about the precise “best day to buy a ticket.” In practice, those patterns are noisy and unreliable. The actionable takeaway is simpler: book early, fly during a cheap week, and depart mid-week. Those three decisions reliably save more money than trying to time your exact purchase date.

Other Ways to Save on Flights

Beyond choosing the right week and day, a few strategies can shave meaningful dollars off your fare:

• Check nearby airports. Fares between two specific airports can vary enormously depending on airline competition at each hub. If your destination airport is expensive, a nearby alternative with more carriers may offer fares 20–30% lower. The extra ground travel is often worth several hundred dollars in savings.
• Be flexible with dates. Even shifting by a single day can move you from a peak-demand departure to a mid-week lull. Use fare calendars on booking sites to spot the cheapest days visually.
• Book separate legs. If your itinerary requires a layover, booking two separate one-way tickets through the connecting city can sometimes be cheaper than a single itinerary. This is perfectly legal and can save money on routes where the airline marks up the connection.
• Set fare alerts. Once you know your destination and target travel window, set alerts on a booking aggregator. Prices fluctuate daily, and a well-timed alert can catch a dip.

What if You Care More About Weather Than Price?

If good weather matters as much as (or more than) a low fare, see our best-time-to-visit guides, which cover hundreds of cities worldwide and show you the overlap between pleasant weather and affordable fares. You can also use our travel weather map to filter destinations by your preferred temperature, precipitation, and humidity—useful if you’re flexible on where to go and want to optimize for both comfort and cost.

Travelers open to last-minute trips can find steep discounts, but the catch is that the cheapest available destinations are often places experiencing off-season weather—cold, rainy, or otherwise unpleasant. If you have the flexibility, the best approach is to identify destinations where weather is nice during a cheap-fare window and set alerts for those routes.

Do Domestic Flight Prices Vary by Country?

Significantly. Domestic fares are especially sensitive to national holidays, school-vacation calendars, and geography. The chart below compares U.S. and U.K. domestic round-trip fares week by week.

U.K. domestic fares spike dramatically in spring and summer—often doubling or tripling their winter levels. This is driven by the strong British holiday tradition (particularly Easter and the summer half-term) and the fact that a smaller, northern country offers few warm-weather domestic escapes. When Britons want sunshine, they tend to fly internationally, keeping winter domestic demand (and fares) low.

Americans, by contrast, can fly to Florida, Southern California, or Hawaii year-round, which spreads domestic demand more evenly across the calendar. The Thanksgiving spike is visible in the U.S. data but far less dramatic than the U.K.’s spring surge. These country-specific patterns are why global averages can be misleading—the best time to fly cheaply depends heavily on where you live.

Do International Flight Prices Vary by Country of Origin?

International fares are less volatile than domestic ones because they aren’t tied to a single country’s holiday calendar. The chart below compares U.S.-origin international flights with non-U.S. international flights.

U.S.-origin international fares tend to run higher because many routes cross the Atlantic or Pacific—long distances that constrain airline competition and increase fuel costs. Seasonal spikes still appear but are less dramatic than on domestic routes: national holidays produce roughly a 3% increase over the annual median for international flights, compared with a 15% spike for U.S. domestic flights during the same weeks.

Non-U.S. international fares (orange line) are lower on average and more stable throughout the year, partly because shorter cross-border flights (e.g., intra-European routes) pull the average down and partly because holiday calendars are more fragmented globally than within a single country.

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