For the third consecutive month, the Case-Shiller 20-City index fell by at least 1.0 percent, with home prices continuing their plummet from the index's peak in July. Nineteen of the 20 cities had a drop in prices in December. The exception was Washington, D.C. where prices rose by 0.3 percent.

While in prior months the sharpest declines had been in the Midwest, the December data shows a more diverse pattern. Tampa — one of the epicenters of the housing bubble — experienced the sharpest price decline at 2.6 percent, followed by a 2.3 percent drop in Detroit and a 2.0 percent decline in Seattle. The situation in Seattle is interesting since the city, like Portland, had previously been shielded from the worst effects of the housing bust. It seems that this is no longer the case as prices in both cities are now falling rapidly.

For more, check out our latest Housing Market Monitor.