NEW YORK -- A last-minute surge in spending seems to have saved the holiday shopping season.

Major retailers including Costco, Gap and Nordstrom on Thursday reported better-than-expected revenue in December. That comes as a relief for stores, which can make up to 40 percent of their annual revenue in the last two months of the year.

Americans spent cautiously early in the season because of the damage after Superstorm Sandy. Then they held back because of the possibility of the U.S. economy falling off the "fiscal cliff," which would've triggered massive budget cuts and tax increases that would amount to less money in their pockets. But shoppers spent more freely in the final shopping days of the year.

Twenty retailers reported that revenue at stores open at least a year - an indicator of a store's health - rose an average of 4.5 percent in December compared with the same month a year ago, according to the International Council of Shopping Centers. That's on the high end of the expected range of 4 percent to 4.5 percent. Only a small group of stores that represent about 13 percent of the $2.4 trillion U.S. retail industry report monthly revenue, but the data offers a snapshot of consumer spending.

"I wouldn't be doing cartwheels that it was a particularly great or strong holiday season, but it could have been worse given the headwinds," said Ken Perkins, president of RetailMetrics, a research firm. "The government and Mother Nature were not as cooperative as retailers would have liked. But it was definitely not as bad as feared."

December's results provide a brighter picture than reports last month that proclaimed that the holiday shopping season was shaping up to be the worst since 2008 when the U.S. was in a deep recession.

To be sure, the season had multiple fits and starts, with healthy spending during certain periods followed by stretches of tepid sales. Overall, revenue for the combined months of November and December rose 3.1 percent, slightly above the 3 percent rise that the ICSC had predicted.

Sales were weak at the beginning of November in the wake of Superstorm Sandy on the Northeast and the U.S. presidential campaign, followed by a surge later in the month during the four-day Thanksgiving weekend. Spending fell off after that until a rush right before and after Christmas when some stores began offering bigger discounts.

Nordstrom, for instance, had a particularly strong December, with revenue at stores open at least a year up 8.6 percent, more than double the 3.4 percent analysts expected. The Seattle-based department store operator said revenue was particularly strong in the last week of the season.

"That last-minute shopping, coupled with post-Christmas bargain hunting and early gift-card redemption, helped propel sales at the end of the month," said Michael P. Niemira, ICSC's chief economist.

Kelly Tenedini, 35, decided to pick up some "filler" gifts for her mom and her sister on the Sunday before Christmas at the Target in the Edgewood Retail District in Atlanta. Tenedini, who spent about $400 during the season, bought a sweater for her mom and gloves for her mother and sister that day.

Tenedini, who works in marketing, said the biggest deal she found was for herself: $50 off a pot and pan set on Target.com.

Manuel Gonzalez, 52, from Manhattan borough of New York City, spent about $150 on the Saturday before Christmas when he went to The Garden State Plaza in Paramus, N.J. He scooped up bargains, including 75 percent off Sketcher sneakers at Macy's.

For the season, he was planning to spend about $400 to $500 for gifts for his three boys, ages 5, 8 and 22 -- the same amount he spent a year ago.

Gonzales, who works at a bank, said he's glad he waited until later in the season to shop: "I am budgeting."

While the last-minute promotions may have drawn shoppers like Tenedini and Gonzalez, they also ate into stores' profits.

For instance, Kohl's said its December revenue at stores open at least a year increased 3.4 percent, beating Wall Street predictions. But the retailer said that the growth came from heavy discounts, and it cut its profit outlook for the current quarter and full year.

"Sales came late in the holiday shopping season and, as a result, were at deeper discounts than planned," said CEO Kevin Mansell. "We are taking the necessary markdowns in the fourth quarter to manage our inventory as we transition into the Spring season."