It’s been a rough start of the year for passengers.

A series of winter storms have led airlines to cancel more than 33,000 flights during the first three weeks of this year. That’s more cancellations than in January 2013 and January 2012 combined, according to masFlight, a data and software company specializing in airline operations.

“It’s been miserable,” said John DiScala, who runs the travel advice site JohnnyJet.com and flies around 150,000 miles each year. “There’s so few vacant seats, so when they cancel one flight, trying to get onto another flight is next to impossible.”

Many stranded passengers have had to wait days — and in a few extreme case up to a week — to get a seat on a flight out.

“I think travel agents are starting to look good to many people,” DiScala adds. “At times like this, who wants to be on the phone, literally for hours, trying to get rebooked.”

One expert suggests passengers may want to take an extra precaution.

“If there’s one good time to buy travel insurance it’s during winter,” says George Hobica, founder of travel deal site AirfareWatchdog.com.

“This winter has been a one-two-three punch so far and there are eight weeks to go,” Hobica says. “It seems like airlines are canceling flights more than ever and sooner than ever at the approach of a storm.”

The hardest hit cities so far this winter: New York, Washington, D.C., Boston, Chicago and Philadelphia.

There are roughly 30,000 daily flights in the United States. On a typical day with no weather disruptions about 200 of those flights are canceled, mostly for mechanical reasons.

The canceled trips still represent a small share of the total number of flights — about 5 percent — and aren’t expected to have a major impact on most airlines’ profits. While airlines lose out on revenue from canceled flights, they also don’t have to pay for jet fuel and some salaries.

(AP)