When is the best time of day to fly if you want the best chance for an on-time flight?
The answer is in today’s Washington Post, which has an interesting set of charts in the metro section about airline on-time percentages by time of day. I looked for the article online and couldn’t find it, so I’ll just discuss it briefly here since the data is very interesting.
At the three DC-area airports (National, Dulles, and BWI), the trend is basically the same. Flights departing before noon have considerably higher on-time departure percentages (typically 85% or so) than flights departing in the afternoon and evening. After 4 PM, the on-time departure percentages get really dicey (between 40-50%). With only a few exceptions, the trend is a steady drop in on-time percentage throughout the day. One notable exception involves flights departing after 11 PM, where the on-time departure percentage suddenly shoots back up. Oddly, however, flights departing in the evening earlier than 11 PM have very low on-time percentages (39% from 10:00-10:59 PM at National, less than 50% at the same time at Dulles).
As for arrivals, the trend is basically the same, with arrivals in the AM being far more on-time (70-80%) than in the afternoon and evening (often 50% or below). Arrivals very early in the morning (before 7 AM), however, have lower on-time percentages, but flights arriving between 7 AM and noon are typically 80% on-time or higher.
I would assume that these trends are not unique to the DC area, but that’s just my uninformed guess. I find the data interesting because it suggests that you’re much better off flying in the morning.
There are more interesting stats in the article, but they mainly pertain to specific flights to-from DC that one should avoid. For example, avoid the US Airways 7PM flight from National to LaGuardia. It is late 88% of the time with an average delay of 65 minutes. Yikes! All of the chronically delayed flights are in the afternoon and evening, and most are flights by Comair and US Airways.