Escape NY! - How to Fly Out of NYC

We all know how terrible flying out of NYC can be with the high potential for delays. Combined, the major airports (JFK, LaGuardia, and Newark) are responsible for ~315,000 departing flights per year, and any New Yorker can tell you at least one horror story involving a delay.  So, how can you avoid being on one of those flights?  Do you choose JFK, LaGuardia, or Newark?  And on which day and at what time should you leave?

There are some who would suggest you avoid delays by simply choosing the most conveniently located airport and, regardless of the day, leaving as early in the morning as you can stand.  This school of thought is not incorrect (flights departing later in the day do indeed have a greater chance of being delayed - and the data shows this) but it is imprecise.  Do you really need to depart at 6 or 7am?  What is the increased risk of being delayed if you leave just a little bit later at 8 or 9am?  A more precise method for choosing a departing airport, day and time to minimize delay needs to be created.  This is what I have attempted to do with the chart below.

Departure Delay Chart (And How To Read It!):
The first thing you'll notice about the below chart is the color; just ignore that for a second.  The left-hand column shows the weekdays, and under each weekday are listed the three NYC airports.  The other columns show the time of day of departure, in one-hour increments.  The percentages in each cell represent how many flights were delayed out of the total.  For example: flying out of JFK on a Sunday between 6-7am typically results in only 7% of flights being delayed, not bad.  However, 29% of flights were delayed that flew out of JFK on a Sunday between 6-7pm; not so good.  The colors (green, yellow, red) are used to highlight low, medium, and high levels of delay.  It makes sense to avoid the yellow and red time slots to better avoid delay.

The chart was assembled using 12 months of historical data on each airport (the mentioned ~315,000 flights), so we can have confidence in the displayed percentages.

The chart is pretty useful for planning your next trip.  If you're trying to start your long weekend and fly out of NYC on a Friday, leaving very early from any airport could work but the chart suggests you have a better option: sleep in later and depart from JFK no later than around noon.  Your potential for delay is still minimal (~15%), even at the later time. Now you can have your cake and eat it too.  There are many other scenarios you can optimize with the aid of the chart.

Taking it One Step Further:
What if you can't help but leave during a yellow or red time slot, how long should you expect to be delayed?  And quite frankly, is there actually a correlation between percentage of delayed flights and average delay time?  I'll be answering these questions in my next blog post; stay tuned!

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SAS was used for this analysis; code is available upon request
Source of data from RITA (Research and Innovative Technology Administration - Bureau of Transportation Statistics)
Time range of flight data: 10/1/2013 to 10/1/2014