What is on-time performance?

What does on-time performance measure?

On-time performance compares what a flight actually did with the timetable the airline published, and reports the proportion that fell inside a tolerance window. The window is a choice made by the organisation compiling the figures, which is why two tables labelled on-time performance can disagree about the same flight.

Two versions are in common use. Arrival performance asks whether the aircraft reached its destination on schedule; departure performance asks whether it left on schedule. They answer different questions for a traveller: departure figures describe the start of a journey and how much slack a connection has, while arrival figures describe when the trip actually ends. A flight that leaves late may still arrive inside the window, and a flight that leaves on time can lose that advantage in the air.

The figures matter because a timetable is not a commitment. The Department of Transportation's consumer guide states plainly that airlines do not guarantee their schedules, and lists bad weather, air traffic delays and mechanical issues among the problems that make it impossible for flights to arrive on time. [3]

How does on-time reporting work in the United States?

The Air Travel Consumer Report is a monthly product of the Department of Transportation's Office of Aviation Consumer Protection, designed to give consumers information on the quality of service provided by airlines. [1] It is divided into sections covering flight delays, mishandled baggage and wheelchairs, oversales, consumer complaints, animal incidents and customer service reports to the Transportation Security Administration. [1] The delay, baggage and oversales sections are built on data collected by the Department's Bureau of Transportation Statistics, and each section is preceded by a short explanation of how to read it. [1]

The reporting duty sits with the airlines. Only the largest U.S. airlines are required to maintain and provide on-time performance data; those carriers must give the percentage for an individual flight by phone on request and post the information on their websites, with special notice for flights that experienced serious delays or cancellations. [3] Aggregate airline and airport figures, and a list of the most frequently delayed flights, appear in the monthly report, while the Bureau's website carries detailed on-time data for the airlines required to report. [3]

Airlines also file statistics with the Department on flight delays, cancellations, bumping and mishandled baggage, and those numbers feed the published report. [5] The cycle is monthly: the September 2026 edition carries July 2026 data, and oversales figures are collected quarterly, so they can be slightly older than the other data in a given month. [1]

Why can airline figures and DOT figures differ?

They measure different things. The figure an airline gives for a flight covers one flight number on one date, while the monthly report gives airline-wide and airport-wide performance plus a list of the most frequently delayed flights. [3] An airline or airport average is not a statement about any single flight, so a strong airport figure can sit alongside a weak record on the particular flight you are booking. [3]

They are also compiled at different moments from different submissions. Carriers post their own flight-level percentages as part of their reporting duty [3], while the monthly report is assembled from the statistics airlines file with the Department through its Bureau of Transportation Statistics [5] [1]. Because the report describes a month that has already ended — the September 2026 edition covers July 2026 — it cannot tell you how an airline is performing this week. [1]

How do you use on-time figures when booking?

Compare like with like. If you are deciding between two flights with similar schedules and fares, the Department's guide suggests choosing the one with the better on-time record. [3] Look the flight number up with the airline, since the carrier's own flight-level figure is what the reporting rules require it to provide. [3]

Time of day matters. Because delays ripple through the day, a departure early in the day is less likely to be delayed than a later flight, and an early flight that does go wrong leaves more rerouting options; if the last flight of the day is cancelled, you may be stuck overnight. [3]

For connections, the guide's advice is to check the amount of time between flights and to ask what happens if the first one is late — and if the answer is unacceptable, take another flight or build a longer connection. [3] Where fares and service are equivalent, it suggests the least-congested connecting airport, so that reaching the second flight is easier. [3] The mechanics of connecting time and of recovery after a misconnection are covered in minimum connecting time and the missed connection action plan.

Delays are often shared rather than individual: if the cause is local weather or air traffic control, all flights will probably be late and there is little the airline can do to speed up a departure. [3] See air traffic control delay. Schedules themselves can move, so departure and arrival times are worth re-checking a few days before travel; see significant schedule change. [3]

Exceptions and limits

• Coverage. The reporting requirement applies only to the largest U.S. airlines; smaller U.S. carriers fall outside it. [3] This page covers U.S. federal on-time reporting only.
• Lag. The headline figures are monthly, oversales data are quarterly, and an edition describes an earlier month. [1]
• Probability, not promise. Airlines do not guarantee their schedules, and weather, air traffic delays and mechanical problems are often beyond an airline's control, so a good record lowers risk without removing it. [3]
• Changes to the guide. The Department's consumer guide, which sets out the flight-level access rules above, carries a notice that some or all of its information may have been superseded by statute or rulemaking and that continued reliance on it is not advised. [3]

Frequently asked questions

Where can I find the on-time percentage for a specific flight?

Ask the airline: the larger U.S. airlines must give it by phone on request and must post it on their websites, flagging flights that had serious delays or cancellations. [3]

How often is on-time data published?

The Air Travel Consumer Report is monthly; the September 2026 edition contains July 2026 data. [1] Oversales figures within it are reported quarterly. [1]

Does the DOT report cover every airline?

No. Only the largest U.S. airlines are required to maintain and provide on-time performance data. [3]

Is a good on-time record a guarantee?

No. Airlines do not guarantee their schedules, and weather, air traffic delays and mechanical issues can still delay a flight with a strong record. [3]

Is the earliest flight of the day the safest choice?

It is one way to reduce risk: an early departure is less likely to be delayed by the ripple effects that build through the day, and it leaves more rerouting options if something goes wrong. [3]

Related pages

Terms: minimum connecting time (MCT), air traffic control delay, significant schedule change. Guides: missed connection action plan. Browse all frequent flyer terms.

Sources

Sources accessed on 18 October 2026. It covers U.S. federal on-time reporting only; individual airline frequent flyer programmes, smaller carriers outside the reporting group and airlines in other markets are not covered.

1. U.S. Department of Transportation, Air Travel Consumer Reports, checked 18 October 2026
2. U.S. Department of Transportation, Fly Rights: A Consumer Guide to Air Travel, checked 18 October 2026
3. U.S. Department of Transportation, File a Consumer Complaint, checked 18 October 2026