Shoppers rummaged through stores for post-Christmas sales starting early Thursday as merchants sought to clear out leftovers and put behind them the weakest holiday season in at least 30 years.

At Natchez Mall, cars almost filled the parking lot by noon Thursday as people took advantage of post-holiday sales, cashed in gift certificates and made returns and exchanges.

&uot;Sales are still great &045; we’re busy with traffic,&uot; said mall Manager Janell Verucchi.

At Natchez’s Wal-Mart SuperCenter, it was busy all day Thursday, said Co-Manager Wayne Bagley.

&uot;It’s at least as busy as last year, mostly with people buying Christmas decorations, which are 30 to 50 percent,&uot; Bagley said.

Not many customers were making returns and exchanges at Wal-Mart Thursday, but that could start in earnest today, Bagley said.

Stores nationwide also saw their traffic increase the day after Christmas.

At the Sears, Roebuck and Co. store in the Burlington Mall in Burlington, N.J., Christine Brown shopped for last-minute gifts for friends.

”I wanted to get something for those people who I had no idea were getting me presents,” Brown said. She planned to buy a few sweaters and nightgowns, which she was pleased to see priced at 50 percent off.

Brown, who arrived at the mall about 7:30 a.m., said she was surprised that more people were not out shopping. A snowstorm on the East Coast the day before made roads slick and may have kept some bargain hunters at home.

Despite a better-than-expected sales surge following Thanksgiving, customers have been reluctant to spend, uninspired by the lack of must-haves and stymied by worries about the economy and jobs.

The compressed season, which was six days shorter than a year ago, also had an impact on consumers, who never quite recovered from the lateness of Thanksgiving and seemed to delay their gift buying even more than usual.

Stores are counting more heavily this year on a spending frenzy during the last week of December, which traditionally accounts for about 10 percent of holiday sales, according to the International Council of Shopping Centers.

They’re expecting consumers to redeem their gift certificates and also pick up a few extra bargains.

Still, there is little hope that the post-Christmas rush will be enough to save merchants from the weakest season in more than 30 years.

Michael P. Niemira, vice president of Bank of Tokyo-Mitsubishi Ltd., expects that sales at stores opened at least a year, known as same-store sales, for the combined November and December period will be up only 1.5 percent.

That’s lower than his already reduced forecast of 2 percent and is the weakest increase since the same-store index started tracking the data in 1970.