What are the odds that your flight will arrive on time? If you’re flying El Al, you can expect to be delayed, arriving more than 15 minutes past the published arrival time, fully 56 percent of the time. That’s significant, and important to factor into your trip planning when traveling on El Al. Or, knowing that, you might want to book your flights on an airline that has a better on-time record.

To be sure, El Al was the worst of the international airlines included in FlightStat’s latest Performance Service Awards survey; most airlines fared better.

For the eighth year running, FlightStats has compiled data on the on-time performance of the world’s airlines, and ranked the carriers accordingly. Here are the on-time arrival stats for the 10 top-rated North American carriers:

1. Alaska Airlines – 87%
2. Delta Air Lines – 85%
3. WestJet – 83%
4. Southwest Airlines – 82%
5. United Airlines – 82%
6. American Airlines – 80%
7. Frontier Airlines – 77%
8. Virgin America – 77%
9. JetBlue Airways – 76%
10. Air Canada – 76%

While the airlines’ reliability has been improving steadily, and has become a selling point in the marketing communications strategy of at least some airlines, even the highest-rated carriers fall well short of 100 percent on-time arrivals. Delta, for example, which lately has made on-time performance an operational priority and a marketing selling point, still arrives late 15 percent of the time. And Delta is among the very best; most other airlines’ records are considerably worse.

For schedule-conscious travelers, knowing which airlines are more or less likely to get them to their destinations on time can be a difference-maker when deciding which carriers to book. And for all travelers, the findings are a timely reminder that the published arrival time is anything but assured.

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After 20 years working in the travel industry, and almost that long writing about it, Tim Winship knows a thing or two about travel. Follow him on Twitter @twinship.

This article first appeared on SmarterTravel.com, where Tim is Editor-at-Large.