Home prices in South Florida posted strong gains in January as inventory drastically dwindled compared to the previous month.

The median sales price of condominiums in Miami shot up 36% to $122,500 in January from $90,074 a year earlier, according to the Miami Association of Realtors. The median sales price of single-family properties jumped 13% to $170,000 from $150,443 in the same period.

Across Florida, the median sales prices of condominums in the month increased 18.8% to $95,000, while prices for single-family homes rose 5.3% to $129,000. The national median existing-home price for all housing types fell 2% in January to $154,700 from a year earlier.

The inventory of residential listings in Miami-Dade County dropped 37% in January to 13,610 from 24,507 a year earlie. In December, the annual drop was only 3.4%. Total housing inventory nationally at the end of January was down 20.6% from the year ago.

“Record demand for Miami properties has caused inventory to rapidly decline, resulting in limited supply,” said MAR Chairwoman Martha Pomares.

“Now home prices in Miami are significantly rising and sooner than expected, as the Miami real estate market continues to outperform the rest of the nation, mostly due to the strong impact of international buyers," she said.

Demand for real estate-owned properties and short sales remains high in Miami-Dade. In January, 56% of all residential sales in the South Florida county were distressed versus 70% in January 2011 and 54% in December.

Contrary to a year ago, there are now more short sales being transacted than REOs, MAR noted.

In Broward County, single-family home sales increased 15% to 911 in January from 813  in January 2011. The median sales price of single-family homes in Broward County was $177,000, up 7% compared to January 2011.

The Realtor group said 49% of all closed residential sales in Broward County were distressed.