How accurate is the fare outlook?

Forecasts made the same way for 106,098 past route-quarters since 2017 missed the actual average fare by 7.3% in the middle case, and the actual fare fell inside the range 78.8% of the time. A route only shows an outlook when its own past forecasts held at least 75% of the time with a median error of at most 10%.

Why is there no "best time to book"?

That needs prices by the day a ticket was bought, and no open data source has them. The DOT data says what passengers paid per quarter, not when they bought.

Which routes have an outlook?

US domestic routes with enough DOT history where past forecasts held: 449 route pages now. Routes outside the US have no open fare data.

How often does it change?

With every new DOT quarter, about five months after the quarter ends. Each published outlook is kept, so later quarters show how it did.

Is the fare outlook in the API?

Yes. The route file in the free JSON API (https://airportmiles.com/api) has it under "fares.outlook", with the 80% range and how past forecasts did on that route. No key, CC0.

AirportMiles

Fare outlook

How we estimate the average fare paid on a US route in Q1 2027, and how well the method did.

US route pages show what passengers paid on average, from the US Department of Transportation's ticket sample. The newest quarter is Q1 2026; the DOT publishes each quarter about five months after it ends. On routes where it has worked before, the page also shows what we expect for Q1 2027: a middle figure and a range that the actual average should fall into eight times out of ten.

An estimate from US DOT data: not a price you can book, not a guarantee, not advice on when to buy.

How it is made

Start from the route's average fare in Q1 2026, the same quarter a year before the one we estimate.
Add the usual change over a year, and take the range from how far such forecasts were off in the past, on routes with a similar number of passengers.
Show it only where the route's own past forecasts fell inside the range at least 75% of the time, over at least 8 quarters, with a median error of at most 10%.
Leave out 2020 and 2021: the pandemic says nothing about normal years.

We tried two richer models: one adding the national trend, one adding each route's seasonal pattern. Both did worse than this plain one, mostly because fares jumped in 2022–2023. The test reruns with every new quarter.

The range comes from how fares moved in past years. A sudden change that history has not seen, such as a sharp rise in fuel prices that lasts, can push the actual average outside it.

How past forecasts did

Forecasts tested: 106,098; Route-quarters since 2017, without 2020–21
Median error: 7.3%; Middle figure against the actual average
Range held: 78.8%; Actual average inside the 80% range
Route pages with an outlook: 449; For Q1 2027

Year forecast	Forecasts	Median error
2017	16,312	6.9%
2018	16,560	6.4%
2019	16,941	6.7%
2023	16,808	9.7%
2024	17,329	7.5%
2025	17,816	6.7%
2026	4,332	8.7%

Backtest on U.S. DOT Consumer Airfare Report Tables 1a and 6 (airline ticket sample), each forecast from the data published before it. Sources

The busiest routes, Q1 2027

Questions

No. The outlook is the average fare all passengers on the route are expected to pay in a quarter, including taxes, across every cabin and booking date. It is not a price you can book, not a guarantee and not advice on when to buy.