Best Time to Book Flights: Day, Weeks Ahead and Season

The best time to book a flight is a window of weeks, not a day of the week. If you are flying from the US, fares hit their lowest average at a predictable distance from departure, and that distance changes with where and when you fly. Here are the windows for domestic, international and holiday trips, this year’s Thanksgiving and Christmas booking dates, and a rule for deciding whether to book today or wait.

How far in advance to book flights

Google analyzed 5 years of Google Flights data for US departures and published its booking windows in October 2026. Each row below gives the number of days out where the average price was lowest, and the range of days where prices stayed close to that low. Inside the range, one week rarely differs much from the next. Outside it, you usually pay more.

Trip	Lowest average price	Low-price range	What to do
Domestic	39 days out	22-57 days	Start watching 2 months out and book inside the range
International	89 days out	50-133 days	Book when a fair price appears; the range is nearly flat
Europe	About 90 days out	49 days or more	Book early; waiting rarely pays
Mexico or the Caribbean	43 days out	24-69 days	Closer in than other international trips
Thanksgiving	34 days out	21-57 days	Book in October
Christmas	56 days out	33-67 days	Book late October to mid-November
Spring break (March or April)	50 days out	29-64 days	Book 1 to 2 months ahead
Summer (July or August)	21 days out	20-47 days	The one window close to departure

Source: Google Flights data for US departures over 5 years, published 5 Oct 2026.

Domestic flights

For a trip inside the US, Google’s analysis puts the lowest average fare 39 days before departure, with a low range of 22 to 57 days. The range is slightly wider than in 2025, but the low point has stayed at 39 days. ARC’s 2025 Air Hacks report, built with Expedia from 12 months of data, lands in the same place: book a domestic trip at least 34 days out, and you could save up to 25% against a last-minute purchase.

For a Saturday 5 December departure, the low range runs from 9 October to 13 November, with the lowest average around 27 October. Start tracking a few weeks before the range opens, so you know what a normal price looks like on the route when it does.

International flights

International fares bottom out earlier, about 89 days before departure. Google calls the average price drop across the 50 to 133 day range insignificant and advises booking as soon as you can. Europe follows the same pattern, with the lowest average about 90 days out and a low range that starts 49 days before departure and stretches back from there. Mexico and the Caribbean are the exception: the lowest average lands 43 days out, within 24 to 69 days.

ARC’s 2025 report points the other way for international trips: tickets booked 18 to 29 days ahead saved up to 17% compared with tickets booked more than 2 months out. With two datasets disagreeing, we would start tracking an international route about 4 months out and book once it reaches a price you have already seen on that route, rather than hold out for a late drop.

Holiday and seasonal booking dates for 2026 and 2027

Day counts are easier to act on as dates. The table applies Google’s averages to this year’s holidays, assuming you leave on the holiday itself; for each day earlier you leave, move every date back by a day. The 2027 rows apply the same averages to example dates, so treat them as reminders to start searching rather than forecasts.

Trip	Departure	Low window opens	Lowest average	Low window closes
Thanksgiving	Thu 26 Nov 2026	Wed 30 Sep	Fri 23 Oct	Thu 5 Nov
Christmas	Fri 25 Dec 2026	Mon 19 Oct	Fri 30 Oct	Sun 22 Nov
Spring break (example)	Sat 13 Mar 2027	Fri 8 Jan	Fri 22 Jan	Fri 12 Feb
Summer (example)	Thu 15 Jul 2027	Sat 29 May	Thu 24 Jun	Fri 25 Jun

As of late October 2026, both holiday windows are open. Thanksgiving’s lowest average falls around 23 October, and its window closes around 5 November. Christmas stays inside its low window until about 22 November.

When to book Thanksgiving flights

Google’s data puts the lowest Thanksgiving fares 34 days before departure, within a range of 21 to 57 days, which is why the cheapest options tend to appear in October. If you can, price the holiday itself too. TSA checkpoint counts show Thanksgiving Day 2025 was the quietest day of that year, with 1,559,165 people screened, while the Sunday after was the busiest, at 3,134,613. Those are traveler counts, not fares, but a day with half the travelers of the peak is worth a look in the Dates view.

Example fares, illustrative only, for one adult in main cabin, searched 22 Oct 2026.

Search	Out	Back	Round-trip fare
Peak dates	Wed 25 Nov	Sun 29 Nov	$468
Fly on the holiday	Thu 26 Nov	Sun 29 Nov	$392
Holiday out, Monday back	Thu 26 Nov	Mon 30 Nov	$341

The route is Denver to Philadelphia, and the search runs 34 days before a Wednesday departure, inside the 21 to 57 day Thanksgiving range. Leaving on Thanksgiving Day instead of Wednesday, and flying back on Monday instead of Sunday, cuts the fare by $127, or 27%, for the same 4 nights away. Google Flights shows “Prices are unlikely to drop before you book”, so the traveler books the Thursday-to-Monday trip with the airline, 35 days before departure, and searches the same flights again the next morning, while the airline’s free 24-hour cancellation is still open.

When to book Christmas flights

Christmas fares bottom out 56 days before departure, within 33 to 67 days. That is 5 days earlier than in Google’s 2025 analysis, and it puts the best deals between late October and mid-November. The holiday itself is quieter here too: TSA screened 2,066,118 people on Christmas Day 2025, against 2,924,593 on Sunday 28 December.

Spring break, summer and the cheapest months to fly

Spring break trips in March or April were cheapest 50 days out, a full week earlier than in 2025, within a range of 29 to 64 days. Summer is the outlier: July and August trips hit their lowest average just 21 days before departure, within 20 to 47 days, so a summer trip booked 3 to 6 weeks ahead is not a late booking by this data. The range ends 20 days out, though, so a booking any closer falls outside it.

If you can choose the month, start with January. CheapAir’s 2024 study of more than 917 million US domestic fares found it the cheapest month to fly, with February second and November and July the most expensive. A January trip cost $125 less on average than a November one.

When do flight prices drop?

Flight prices do not drop on a schedule. They move constantly: CheapAir counted 49 price changes on average from the day a trip goes on sale, by about $98 each time. Most US airlines publish fares about 330 days, or 11 months, before departure, according to the same study. Averaged across trips, the result is a curve: prices start high, ease into a low window, then climb again in the final 3 weeks.

CheapAir’s single cheapest day averaged 42 days before departure, 3 days from Google’s 39, so two separate datasets point to the same 5 to 6 weeks for a domestic trip. Its booking zones show what you pay for missing that window in either direction.

Days before departure	Average fare vs the 21-74 day window	What you get for it
206-315 days	About 36% more	First pick of flights, seats and cabins
75-205 days	About 14% more	Good choice at a moderate premium
21-74 days	Lowest	CheapAir’s prime booking window
14-20 days	About 8% more	Fare increases start around 21 days out
7-13 days	About 26% more	Fewer seats and higher fares
0-6 days	About 59% more	No federal 24-hour hold or free cancellation

Source: CheapAir 2024 study of US domestic fares.

Booking very early buys choice, not a lower price. That is a fair trade for a family that needs seats together or a route with one flight a day, and a poor one when price is the only thing that matters.

Best day of the week to book flights

There is no dependable cheapest day to book. Three large fare datasets give three different answers, and the edge in each is small.

Dataset	Data behind it	Cheapest day to book	Size of the edge
Google Flights, Oct 2026	5 years of US departures	Wednesday, narrowly ahead of Tuesday	About 1.4% below Sunday, the most expensive
ARC and Expedia, Jan 2025	12 months of ARC data	Sunday	Up to 8% below Friday, down from 13% a year earlier
CheapAir, Oct 2024	917 million US domestic fares	No day stands out	Average low fare varies by less than $1

So do flight prices go down on Tuesdays? Not in any of these datasets. Tuesday came second in Google’s ranking, and even the winner, Wednesday, saved about 1.4%, roughly $5 on a $350 fare. A rule whose winner changes from one dataset to the next is not one to plan a purchase around.

The day you fly is a different matter. Leaving on a Monday and returning on a Tuesday or Wednesday cost about 14% less than weekend trips in Google’s data, and up to 20% less than a domestic trip that leaves and returns on a Sunday, so picking your travel days is worth about 10 times as much as picking a booking day. The flight itself matters too: the same data put a nonstop at about 20% more on average than a trip with a connection.

Do flight prices drop at 3am or late at night?

We found no airline, regulator or published fare study showing that fares drop at 3am, overnight or at any set time of day. With a fare changing 49 times on average over its life, a lower price you happen to see after midnight is consistent with ordinary movement, not a pattern you can plan on. Let a price alert watch the route instead of setting an alarm.

Should you book now or wait?

At the search screen, the question is whether the price in front of you will be beaten before you fly. Nobody knows for certain, but the windows above, Google’s price tips and the 24-hour rule settle most cases.

Google Flights’ Tips line can say “Prices are unlikely to drop before you book”, which Google shows only when it predicts that with a high degree of confidence, or “Prices are likely to increase” with an expected amount. Both come from past price trends, and Google adds that prices may not behave as it expects.

If you are still ahead of the window, price tracking in Google Flights does the waiting: track your dates, or “Any dates” if you are flexible, and Google emails you when the price changes significantly or is likely to rise. Hopper’s app makes the same kind of call and says it tells you when to book; treat its advice and Google’s as forecasts, not promises.

Decide whether to book today or wait

1. Count the days until departure and find your trip’s low range in the first table on this page.
2. Read the Tips line on Google Flights for your exact dates and flights.
3. Book now if you are inside the range and the tip says prices are unlikely to drop or likely to increase.
4. Turn on price tracking if you are still ahead of the range, and set a reminder for the day it opens.
5. Book with the airline rather than an agency when you are 7 or more days out, so the 24-hour rule applies.
6. Search the same flights again the next day, and cancel and rebook inside 24 hours if your airline offers free cancellation and the fare has dropped.

If your dates might still move, check the fare type as well as the timing. As of October 2026, Delta charges no change fee on tickets for travel starting in the 50 US states, Canada, Puerto Rico or the US Virgin Islands, except Basic fares, though you pay the difference if the new flight costs more. On a fare like that, booking early inside the window costs you little flexibility.

When to book student fares, error fares and sale fares

Student fares are a different price, not a different calendar: price them inside the same window as everyone else and book whichever is lower, the student fare or the cheapest public fare for your dates.

Error fares, prices published by mistake, ignore the windows on this page. They appear on no calendar, so they reward a route you already track rather than a date you circled.

Airline sales run on the airline’s timetable, not yours. A sale fare is worth taking when it lands inside your low range or beats the lowest price you have tracked for those dates; outside the range, compare it with what the route normally costs before calling it a deal.