You’ve probably heard about the importance of seeking out alternate airports, and the latest stats from the Department of Transportation show why.In fact, using an alternate airport can mean the difference between your flight being on-time, and very late, or never leaving at all.Most New York airports– JFK, LaGuardia, and Newark– have very poor on-time records.But there’s one important exception: Long Island’s small Islip Airport, also known as McArthur. It ranks among the best in terms of on-time performance.At San Francisco’s alternate airport, Oakland, more than 80% of its flights were on time in recent months.SFO couldn’t even reach 70% over the same time period.In Chicago, O’Hare often has the country’s worst on time record, but nearby Midway Airport is usually much better.And in South Florida, many road warriors avoid Miami altogether.Fort Lauderdale is better, but West Palm Beach is among the best in the nation.Check out more Daily Travel Tips.