Santa left homeowners—and builders—two big lumps of coal in their stockings in December, according to two major home price indices, each of which today released data showing 2008 declines.

The largest slide came from S&P/Case-Shiller indices, which noted declines across all three indices: national (down 18.2%), its 10-city composite (down 19.2%) and its 20-city composite (down 18.5%). “The broad downturn in the residential real estate market continues,” said David M. Blitzer, chairman of Standard & Poor’s index committee. “There are very few, if any, pockets of turnaround that one can see in the data.”

Indeed, none of the major metro housing markets tracked by Case-Shiller recorded even the smallest of home price gains in December.

In terms of geography, Case-Shiller’s 10-city composite includes Boston, Chicago, Denver, Las Vegas, Los Angeles, Miami, New York, San Diego, San Francisco, and Washington, D.C. Its 20-city composite covers those same 10 cities plus Atlanta, Charlotte, Cleveland, Dallas, Detroit, Minneapolis, Phoenix; Portland, Ore.; Seattle, and Tampa.

The Federal Housing Finance Agency (FHFA), which develops its index based on conforming loans owned or guaranteed by Fannie Mae and Freddie Mac across the country, also showed continuing weakness. According to its data, purchase-only home prices fell 8.2% in 2008’s fourth-quarter, compared to the same time one year ago.

“Price declines continued in the fourth quarter although not as rapidly as some had expected,” FHFA Director James B. Lockhart said. “We are hopeful the housing initiatives announced last week by President Obama will begin to provide much-needed stability to the housing markets.”

On a monthly basis, though, the FHFA, showed the tiniest improvement: an increase of 0.1% in December 2008, compared to the previous month. That’s due to monthly home price gains in a number of Census regions: Mountain (up 0.1%), West North Central (up 2.7%); West South Central (up 1.3%), East North Central (up 0.1%), and East North Central (up 0.7%).

Alison Rice is senior editor, online, at BUILDER magazine.