Whether it’s end-of-year bookkeeping or just plain generosity around the holidays, donations to New York City’s social service charities have picked up in the last few weeks. The surge follows the lull in the wake Hurricane Katrina, which caused one of the worst autumns in memory for local fund raising.

“When the big mailbags came in last week, we said, ‘We’re back!’ People around here were just jumping up and down,” the executive director of City-meals-on-Wheels, Marcia Stein, told The New York Sun. “September and October were down 25% to 30%. Now money is pouring in in a very generous way.”

The organization, which delivered more than 2 million meals to homebound seniors last year, saw $111,000 in donations arrive on December 21, the most lucrative day since its founding in 1981.

Most organizations will not have data on their year-end contributions until mid-January, but many of them report that donations are increasing.

“Money was coming in in the last couple of weeks,” a spokeswoman for the Robin Hood Foundation, Suzanne Bronski, said, adding that the poverty-fighting organization collected more than $55 million this year, matching last year’s results.

Many charities make up to a third of their yearly income in November and December. This year, however, natural disasters like Hurricane Katrina and the recent earthquake in Pakistan were drawing money away from local charities, which saw donations plummet by as much as 50%, according to a December 5 article in Crain’s New York Business.

City Harvest, which feeds more than 260,000 people a week, has a $170,000 hole to plug, according to a spokeswoman, Patricia Barrick. Though she said she does not think the organization will recuperate the entire amount, she said recent donations have met expectations and that City Harvest will be “able to right the ship a little bit.”

Local social service organizations are the most likely charities to see their donations decline after a major natural disaster, a recent chairman of the Giving USA Foundation, Henry Goldstein, said. “They need the money most and have the hardest time raising it.”

In September, President Bush signed into law the Katrina Emergency Tax Relief Act of 2005, which abolished the limit on tax deductions for individuals’ cash donations made between August 28 and December 31.

The law has proved quite lucrative for hospitals, universities, and major arts institutions, experts say, but not for smaller charitable groups.

“We’re not benefiting from that, as far as I know,” a spokeswoman for the Food Bank for New York City, Carol Schneider, said. “Our individual donors are typically not making large donations.”

“There are not that many individuals who give to their capacity,” a freelance fund-raising consultant for small nonprofits in New York, New Jersey, and Pennsylvania, Ruthellen Rubin, said.

Why, then, are donations increasing again?

“American people have a pretty short focus,” Mr. Goldstein said. Charities may suffer in the short run as their traditional donors give to disaster relief organizations, he said. As attention shifts, they “tend to recover over time. That’s what happened after 9/11. … If you take the past as a guide, the kinks are likely to come out.”

Some organizations did not see a significant decline in donations at all this year, he added, citing Project Renewal and the Women’s Prison Association, of which he is a board member. Representatives of the association were unavailable for comment yesterday.