Millions of holiday travelers heading to the nation's airports over the next week can take some solace: neither the Christmas nor Thanksgiving travel seasons are the busiest of the year, a USA Today analysis shows.

Airports are crowded and hectic this time of year, but much of the perception about holiday air travel is wrong, according to the Bureau of Transportation Statistics (BTS) and the Federal Aviation Administration.

Flight volumes are lower during the holidays than peak days in summer, and delays are typically less severe, data show.

Darryl Jenkins, an academic and airline consultant, said the idea that the holidays are the busiest air-travel time of the year "has been conventional wisdom for as long as I can remember."

But holiday air travel, the 2006 data show, does not crack the top 20 busiest days

"Make no mistake, they are very busy days," says American Airlines spokesman Tim Wagner. "But we have busier days in the summer, and we have more of them."

Last year, the Thursday and Friday before Christmas — Dec. 21 and 22 — ranked as the 23rd and 24th busiest air-travel days of the year with 20,761 and 20,760 flights, respectively, according to the BTS. The airlines' official schedules for 2007 show a similar trend, says OAGback Aviation Solutions.

On Nov. 22, 2006, the Wednesday before Thanksgiving — often considered the busiest day of the year — ranked as the 36th busiest, according to the BTS. Its 20,686 flights were 201 fewer than the busiest day of the year, Friday, Aug. 4, 2006.

One holiday in 2006 beat both Christmas and Thanksgiving. The Friday before Labor Day ranked 14th for most flights.

The bottom line: taking a flight on virtually any Thursday or Friday during the summer is worse. Seats are just as packed, there are more flights and the odds of being delayed is higher.

Jenkins said several airlines confirmed that flights and passenger loads are higher during the summer.

Travel experts warn that holiday travelers are susceptible to severe weather that can wreak havoc on the aviation system. Last year a massive snow storm hit holiday travelers in the days before Christmas. On Dec. 22, 64 percent of flights did not arrive on time, the worst day of the year, according to the BTS.

Meanwhile, airlines are predicting 2.5 million people will take flights on the four peak days this holiday season: Wednesday, Jan. 2; Friday, Dec. 21; Thursday, Dec. 27; and Wednesday, Dec. 26.