OnTimeIndex

OnTimeIndex

Guides

Every tool on this site reduces the federal on-time record to a number. These guides explain how to read those numbers — the difference between a median delay and a worst-case one, why a high on-time rate can hide a bad flight, and what the five DOT delay causes actually mean. Every figure any of them cites can be reproduced from the public Bureau of Transportation Statistics dataset.

How to Tell If a Flight Route Is Reliable Before You Book

On-time rate, median vs. 90th-percentile delay, and cancellation rate — what each number on a route actually tells you, and why one good headline figure can hide a bad flight.

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How Much Layover Time Do You Actually Need?

Airlines sell connections on their minimum connection time, not on whether the inbound flight arrives in time to make them. Here's how to read the real misconnection risk from the arrival record.

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Which U.S. Airline Is Most On Time? How to Read the Rankings

An airline can lift its on-time rate by cancelling the flights it would have run late. Why you have to read cancellation and diversion rates next to the on-time number, never on their own.

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Comparing Two Airlines: What Actually Predicts a Late Flight

When two carriers fly the same route, which one is the safer bet? The five figures that matter, why the worst-case delay matters more than the average, and how to read a head-to-head honestly.

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What the Five DOT Delay Causes Mean

Carrier, weather, National Aviation System, security, and late-arriving aircraft — the federal delay-cause split decoded, including why the biggest single cause is often just yesterday's delays catching up.

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Does Flying Early Really Mean Fewer Delays?

The oldest piece of travel advice there is — book the first flight out. It's mostly true, and the federal record shows exactly how much on-time rates decay as the day goes on, airport by airport.

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The Best and Worst Months to Fly, and Why

Summer thunderstorms and winter snow drag on-time rates every year, and the pattern is remarkably stable. Which months run late, how big the seasonal swing is, and why it's weather more than the airline.

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