This year, however, if you snooze, you lose.
Airfares are climbing with no leveling-off in sight. The cheapest fares likely are the ones you're seeing now. And if you hope Amtrak will supply a cheaper alternative, forget it.
The smallest sliver of promise is that airlines over the next 10 days may offer lower fares on a meager number of seats for Thanksgiving week — fringe-time seats such as the morning bleary-eye flight or the red-eye express.
"It's nearly 100 degrees outside, so it's sort of hard to be shopping for Thanksgiving. But you want to shop early, there's no doubt about it," said Rick Seaney, founder of FareCompare.com. "The sweet spot to start shopping is mid-August for that holiday travel. It's going to be difficult to catch, but at least you'll have a chance."
A Mid-Atlantic AAA spokeswoman agreed.
"The rule of thumb used to be wait until after Labor Day. But the sooner you have your travel plans in order, the better off you are," Ragina Averella said.
The difference in price between holiday and non-holiday prices is eye-popping.
A Thanksgiving traveler departing Baltimore-Washington International Thurgood Marshall Airporton Nov. 20 for Los Angeles and returning Nov. 25 will pay $225 more than for the same trip in October. A round trip to Houston on AirTran using the same travel window is $309 more.
Even short hops along the Eastern Seaboard are considerably higher. A Southwest flight to Long Island that leaves the Tuesday before Thanksgiving and returns the Sunday after is $150 more than such a trip one month earlier, while an AirTran round-trip ticket to Orlando, Fla., is $169 higher.
"They are definitely gouging people during the holidays," said Kate Hanni, founder of FlyersRights.org. "In general the airlines are wicked high on their fares during the holidays."
But Seaney said it's a simple case of supply and demand.
"The kids in my neighborhood charge three times more for lemonade in the summer than they do in the fall. And the reason is, it's because they can," Seaney said. "Airlines have a hot product at Thanksgiving and Christmastime. Tickets are like an iPhone5."
On Amtrak, a round-trip ticket from Baltimore to New York City will cost $74 more in November than in October; a ticket to Boston is $224 higher. Meanwhile, Greyhound has bumped up some fares (Providence, R.I.) while lowering others (New York City).
A number of factors are driving airline ticket prices higher, experts say. Fuel costs are up. The economy has forced airlines to cut back on the number of flights they offer. Mergers have reduced competition and consumer options. At BWI, for example, the merger of Southwest and AirTran means about 70 percent of the traffic is controlled by one entity.
Even Spirit Airlines — BWI's newest low-cost carrier, which begins service in September — will have higher fares. A round-trip ticket to Fort Lauderdale, Fla., will cost $150 more at Thanksgiving, and baggage and carry-on fees add anywhere from $30 to $85 to the price.
Seaney said airlines have few windows when they don't have to offer discounts to ensure every seat is filled.
"It's their job, and it's expected by their investors, to make the most they can on every seat on every flight," he said. "The airlines are going to be reticent to release cheap seats for holiday travel."
Last year, airlines were successful in raising fares nine times in 22 attempts, accounting for as much as a 20 percent increase over 2010 prices. Ticket prices through the first quarter of the year were up nearly 7 percent over the same period last year, according to the Bureau of Transportation Statistics.
Last Thanksgiving, Maryland air travel increased 3.1 percent after three years of lackluster activity tied to the economy. The rise came despite airfares that averaged 20 percent above 2010 prices, Averella said.
Customers hoping to snap up cheap holiday fares at the last minute will be out of luck.
"Those days are over," Seaney said. "If you go back and look at 2009 during the recession, yeah, they were just looking for anyone able to pull their wallet out of their pocket. It just doesn't tend to happen that often now."
To get the lowest Thanksgiving fares, the experts say consumers should:
•"Fly hungry, which means taking that first flight out, fly at lunchtime or fly at dinner time," Seaney said.
•Know how much you're willing to sacrifice to get a cheap ticket.
"I don't mind getting up at Oh-Dark-30 to get a lower fare and to avoid the likelihood of delays at crowded airports," Averella said.
•Avoid the Wednesday before and the Sunday and Monday after the holiday.
"If you leave on a Tuesday and come back on a Saturday, you can usually save anywhere from 15 to 25 percent," Seaney said.
•Even after you've purchased tickets, keep monitoring prices. "If there's a change in your favor, sometimes airlines are willing to make an adjustment or give you a credit," Averella said.
But, finally, travelers should keep in mind that there comes a time when holiday tradition triumphs.
Said Seaney: "Sometimes you go to grandma's because if you don't go to grandma's she's going to hit you over the head with a rolling pin and it doesn't matter what it costs."