Flight Delays: 5 Things You Must Know About the Weather

May 7, 2011— -- When you think "bad weather" and delayed flights stacking up at the airport, you think blizzards, right? Sure, and no doubt about it, this has been a hellacious winter.

But listen to Air Line Pilots Association First Vice President Capt. Sean Cassidy (he's also a veteran pilot with Alaska Airlines); bad weather and horrendous delays can happen anytime, anywhere. "Don't forget we saw snow in Vegas this year," the pilot said. And some of you will remember when the white stuff came down in Dallas, just in time for the Super Bowl.

And while December, January, February and even March can be truly awful, don't think weather-related flight delays will disappear now that winter has gone. Indeed, the fun is just getting started.

Why you should care: "The total cost of domestic air traffic delays to the U.S. economy was as much as $41 billion for 2007, including $19 billion in raised airline operating costs," according to a 2008 congressional report. "Beyond that, it wasted passengers' precious time -- your time -- and the report even puts a dollar figure on that, as well: $12 billion.

Which is why I put together this list of five things you must know about spring and summer weather before your next flight. Hint: Make sure your smartphone and iPad are fully charged before you head to the airport.

For more travelnews and insights, view Rick's blog at farecompare.com.

1. Summer weather can be worse than winter.

Did you know? Bad weather causes 70 percent of all delays and, according to the Federal Aviation Administration, summers storms are worse. "Unlike winter storms, which take time to develop and move slowly, summer storms can form quickly, stretch for hundreds of miles and travel rapidly over large portions of the country." And, of course, as flights get grounded, the dominos begin to fall and a chain reaction of delays affects airports across the nation.

If you like numbers, the government's Bureau of Transportation Statistics has plenty. During the most recent winter (October 2010 through February 2011), for instance, the worst month for weather-delayed flights was December, with 36.67 percent delays. But May and June were even worse for delays, and July was nearly as bad.

2. Thunderstorms are nastier than you think.

To pilots, thunderstorms mean danger, which is why (in coordination with air traffic controllers) they practice "lateral and vertical avoidance" when they become aware such conditions are building up. "Depending on the nature of the thunderstorm activity, you might fly as much as 20 miles or more around a thunderstorm," Capt. Cassidy said. And, yes, while there are thunderstorms in winter, they are generally far more frequent -- and intense -- in the summer months.

And don't forget thunderstorms' ugly step-children: turbulence and hail. "Hail competes with turbulence as the greatest thunderstorm hazard to aircraft," according to an FAA manual for pilots.

3. Watch out for summer ice.

Ice in summer? Planes fly high and it can occur in spring and summer. The author of the Ask a Flight Instructor blog noted he once picked up some "serious rime ice" on the edge of a summer thunderstorm. It happens.