Researched planning guide based on Google Flights and Expedia’s 2026 U.S. fare analyses, Google Flights Help, U.S. DOT refund guidance, and Delta fare rules. Regional figures reflect historical group averages.
Sources checked November 11, 2026.
If a flight that fits your trip drops below its usual price, you can buy it even if departure is more than 90 days away. The better question is what a good fare looks like for your dates, airports, and baggage needs.
Start watching early enough to see a few prices. Then compare the flights you could actually take. A useful booking window for a flexible weekend in California can look very different from one for a long-haul trip or a cruise with a fixed departure.
When to book cheap flights by destination
Google looked at five years of aggregated Google Flights data for U.S. departures. The results show when average fares were lowest across groups of trips. Your flight can be cheapest outside its group’s window. Google Flights’ 2026 airfare analysis.
| Trip from the U.S. | Lowest average | Historical low-price window |
|---|---|---|
| Within the U.S. | 39 days | 22–57 days |
| International overall | 89 days | 50–133 days |
| Europe | 90 days | 49 days or more |
| Mexico or the Caribbean | 43 days | 24–69 days |
Google found little average price difference within its broad international low-price window. The Europe figures put the average low at 90 days, with lower prices historically available 49 days or more before departure. If you find a good transatlantic fare early, use the extra time to check the dates and fare rules while the price is available.
Expedia’s U.S. report found its lowest average domestic economy fares 15–30 days out. For international economy, it reported average savings at 31–45 days compared with buying six months or more ahead, and a lower average still at 8–15 days in its sample. The two reports use different datasets. A late-booking average can include travelers whose routes and schedules differ from yours, so it offers little assurance about the specific seats you need. Expedia’s 2026 Air Hacks Report.
Which airports should you compare?
U.S. theme parks and city breaks. For Anaheim, compare Orange County (SNA), Long Beach (LGB), and Los Angeles (LAX). For Orlando, price the Orlando airport first and check Tampa only if the savings cover the extra time and ground transportation. Run each search for the whole party, including bags and any seats you would pay to select.
Hawaii. Search for the island where you’ll spend your first night. If another island has a lower fare, price the additional flight, luggage, and connection time before deciding. For a two-island trip, compare a multi-city ticket that flies home from your second island with a round trip plus the extra interisland leg.
Europe. For a two-city vacation, price a multi-city ticket into one city and home from the other. Compare it with the round-trip fare plus the train, extra flight, or overnight stay you would need to return to the first airport.
Japan and other long-haul trips to Asia. Use the international range as a reminder to check early. Google’s report gives no separate Japan or Asia window. For Tokyo, compare Haneda (HND) and Narita (NRT) with the transfer to your hotel included. If you finish in a different city, check what it costs to fly home from there.
Mexico, the Caribbean, and cruise ports. Track the airport you can realistically use, with the transfer included. Apply the Mexico and Caribbean benchmark when you’re flying to those destinations. A flight within the U.S. to board a Caribbean cruise uses the domestic benchmark. For a sailing, aim to arrive the day before and compare airfare, hotel, and port transfers together.
Change your travel days before your booking day
In Google’s analysis, Wednesday purchases averaged about 1.4% less than Sunday purchases. Expedia found a different cheapest purchase day, Friday. Google’s Monday departures with a Tuesday or Wednesday return averaged about 14% less than weekend flights in its comparison. Its nonstop fares averaged 20% more than connecting fares. Use those differences to choose what to test on your route. Google Flights analysis. Expedia’s report.
For holiday planning, Google’s historical low-price windows were 21–57 days for Thanksgiving and 33–67 days for Christmas. Its spring-break window was 29–64 days for March or April departures. For trips in July or August, it was 20–47 days. Start monitoring well before the relevant window when you need particular flights or several seats. Google’s seasonal fare breakdown.
Set up price alerts and compare the full fare
- Run the search with your real constraints. Set the party size, cabin, and acceptable stops. Use the date grid or price graph to see what moving the outbound or return by a day or two does to the total. Google Flights fare-search tools.
- Turn on tracking. Track your preferred dates and use Any dates if you can move the trip. Keep a separate alert for a backup airport or acceptable nonstop if that choice matters to you. Google Flights price tracking.
- Compare like for like. Look at both the Best and Cheapest tabs. On the cheapest result, check the seller, bag rules, seat costs, airport changes, and whether you have to collect and recheck bags on a self-transfer. Then verify the total at checkout. Google’s explanation of the Cheapest tab.
- Decide what you’d pay before the alert arrives. If the fare is below your target, the schedule works, and the restrictions fit, buy it. If it’s above your target and you have room to move, check the neighboring dates or airports before waiting for another drop.
What to do if the price drops after booking
Check the ticket rules and compare the replacement in the same fare class. Delta, for example, says an eligible change to a lower fare may leave an eCredit after applicable fees. Verify the amount and expiration before confirming a change, and check whether seat assignments and extras carry over. Delta’s ticket change and fee policy.
For qualifying bookings made directly with the airline at least seven days before departure, the U.S. Department of Transportation requires a 24-hour penalty-free cancellation option or a 24-hour unpaid fare hold. Airlines can choose which to offer. Third-party bookings follow the seller’s policy for this purpose. If you’re considering canceling and rebooking, check that the replacement is still available and what happens to any extras you bought. U.S. Department of Transportation refund guidance.
Related planning
If the flight is part of a cruise budget, use our guide to comparing cruise deals to price the sailing and its extras alongside the airfare.
Featured photo by kitzstocker.
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