We’ve all been there before. Sitting in the airport, anxiously awaiting a flight that has been delayed a few hours, staring out into a picturesque sunny sky over a clear runway in complete confusion. What caused this delay?

Our Fare Experts do not have all the answers. But a bit of investigation of the Department of Transportation’s Air Travel Consumer Report yields some very interesting information regarding flight delay causes and the top airports when it comes to on-time performance.

Top U.S. Airports for On-Time Flights

Let’s start with the good news, here are the best major airports when it comes to on-time departures and arrivals:

Note: Ranked by percentage on-time performance in January 2012 (higher is better), which was the latest data available

Departures

Honolulu (HNL) – 92.2% Tampa (TPA) – 89.7% New Orleans (MSY) – 89.1% Memphis (MEM) – 88.9% Salt Lake City (SLC) – 88.9%

Arrivals

Honolulu (HNL) – 89.5% Dallas – Love Field (DAL) – 89.4% San Jose, Calif. (SJC) – 89.1% Albuquerque (ABQ) – 88.7% Memphis (MEM) and Salt Lake City (SLC) tied – 88.5%

These statistics are impressive, all the best airports are hovering near 90% in on-time performance. This probably comes as a surprise to many folks, who feel as though they are always stuck in some sort of a delay. While most of these airports are relatively busy, it’s safe to say that none of them are within the top 15 busiest airports in the United States. It is likely that less runway and airspace congestion are big reasons why these airports are top on-time performers.

Honolulu (HNL) is the major hub for Hawaiian Airlines, who advertises itself as the top on-time airline in the U.S. These stats seem to support that claim. (The beautiful weather probably helps a bit.) Another interesting connection is that both Memphis and Salt Lake City airports are Delta Air Lines hubs. In both cases, Delta dominates the airspace and runway.

Worst U.S. Airports for Flight Delays

Now to check out the worst offenders when it comes to delays. Warning, the results may (or may not) surprise you:

Departures

San Francisco (SFO) – 77.2% Newark (EWR) – 77.9% Chicago (ORD) – 78.1% Phoenix (PHX) – 79.8% Houston (IAH) and Chicago (MDW) tied – 81.4%

Arrivals

San Francisco (SFO) – 72.9% Newark (EWR) – 74% Phoenix (PHX) – 76% New York City (LGA) – 79% Seattle (SEA) – 79.5%

Before bashing any of these airports, in all but two of the above, 3 out of every 4 flights will leave on time. Those are odds I would likely take based on my bad luck with delays.

The two worst airports for delays are San Francisco International Airport and Newark-Liberty International Airport, both United Airlines hubs. I am hesitant to say this is an issue with United, but more likely due to the crowded runways and airspace. Both of these airports are in the top 20 busiest airports in the U.S. and serve as major international gateways. Neither of the airports had been adversely affected by major weather issues this winter, so it’s unlikely to see the delay situation improve. Houston (IAH) and Chicago (CHI) are also major United Airlines hubs that made the list.

Seattle was a bit of a surprise to me, but weather delays may be a bigger factor here. Seattle-Tacoma International Airport is a hub for Alaska Airlines, which means two of the most popular destinations are Denver, Colo., and Anchorage, Alaska. With so many flights to these wintry cities, delays are most likely due to bad weather. As for Phoenix, a US Airways hub, there’s not much of a weather excuse.

Top Reasons for Flight Delays

Possibly the number one question that gate agents are trained to avoid is “Why is my flight delayed?” If you never get a straight answer to this question, then you probably aren’t alone. A quick read on the flight delay classifications might help detail why gate agents are so vague. The classifications assigned by BTS.gov to each type of flight delay are pretty ambiguous.

National Aviation System Delay – 31% (Delays and cancellations attributable to the national aviation system refer to a broad set of conditions — non-extreme weather conditions, airport operations, heavy traffic volume, air traffic control, etc.) Late Arriving Aircraft Delay – 30% (Previous flight with same aircraft arrived late which caused the present flight to depart late) Air Carrier Delay – 25% (The cause of the cancellation or delay was due to circumstances within the airline’s control (e.g. maintenance or crew problems, etc.) Canceled – 9% Extreme Weather Delay – 3% (Significant meteorological conditions, actual or forecasted, that, in the judgment of the carrier, delays or prevents the operation of a flight.) Diverted – 1%

Security only accounted for 2 total delays, making it not even significant enough to make the list.

To sum up, 55% of flight delays can be traced back to the airline, be it an “air carrier delay,” like a tardy pilot, or a “late-arriving aircraft delay,” which the airline is unable or unwilling to supply a different aircraft. Interestingly enough, extreme weather is only responsible for 3% of delays. Even with a mild winter, this is quite a surprise considering the data used for analysis is from January. To rule out any strange weather anomalies, I compared January 2012 to 2011, and the percentage was nearly 3% as well.

With 30% of flights delayed because of late-arriving aircraft, we always recommend checking the status of the previous flight in addition to checking the status of your flight. Several airlines, including United, make this really simple by including a note on their flight status page about where the aircraft is coming from. (In addition to weather conditions, which is useful.)

Tips to Avoid Delays

There is no easy answer to this question, but the best advice is to fly at non-peak hours. Avoid rush hour, especially in busy airports or major cities. When runways and airspace become congested, planes end up circling the airport several times before landing or wait in long lines just to take off. On connecting flights, be sure to leave enough time between flights in case of a delay. Usually airlines will be able to place you on the next flight should you miss your connection, though.

Ultimately, bring a good book and some tunes so if a delay does arise, you can relax. Do not let the stress of a rather common occurrence get the best of you.