U.S. home prices rose in January after three months of declines. A tight supply of homes might have helped boost prices and offset sales slowed by cold weather.

Real estate data provider CoreLogic says prices rose 0.9 percent in January after dipping 0.1 percent in December. Over the past 12 months, home prices have risen 12 percent, the biggest year-over-year gain in more than eight years.

CoreLogic's price figures aren't adjusted for seasonal patterns, such as winter weather, which can depress sales.

Snowstorms and low temperatures contributed to a sharp drop in sales of existing homes in January. The National Association of Realtors said sales plunged to their lowest level in 18 months. Still, the number of homes for sale remained low, a factor that might have helped increase prices.

Home sales and construction have faltered over the winter, partly because the weather has likely discouraged many Americans from house-hunting. The average rate on a 30-year mortgage is also about a percentage point more than it was last spring, which means buying costs are higher.

Most recent housing reports suggest that the market is slowing. Economists think the housing recovery could pick up once the spring buying season begins, though likely at a slower pace than last year.

A measure of signed contracts was unchanged in February. Signed contracts usually lead to a finished sale in one to two months. And builders broke ground on 16 percent fewer homes in January than in December, the government said last month. That was the second straight decline.

Other price gauges are falling. The Standard & Poor's/Case-Shiller 20-city home price index dipped in December, the latest period for which data are available, and its year-over-year gain slowed.

Nationwide, home prices are still 17 percent lower than at the peak of the housing bubble in April 2006, according to CoreLogic. Prices have set highs in three states: Louisiana, Nebraska and Texas. They are within 10 percent of their peaks in 19 additional states.

The five states with the biggest price gains in January, compared with a year earlier, were Nevada, where prices rose 22.2 percent; California, 20.3 percent; Oregon, 14.3 percent; Michigan, 13.7 percent; and Georgia, 13.4 percent. Mississippi was the only state to report a price decline.