U.S. home prices jumped 12.2 percent in May from a year ago, the most in seven years, real estate data provider CoreLogic said Tuesday. The increase suggests the housing recovery is strengthening.

Prices rose 26 percent in Nevada to lead all states. It was followed by California (20.2 percent), Arizona (16.9 percent), Hawaii (16.1 percent) and Oregon (15.5 percent).

Home prices rose from a year ago in 48 states. They fell only in Delaware and Alabama.

The Phoenix-Mesa-Glendale area had the second-largest gain among 100 large metro areas, with home prices going up 18.3 percent, including on distressed properties (such as foreclosures and short sales), or 16 percent excluding distressed properties. No data were listed for Tucson.

CoreLogic also says prices across the U.S. rose 2.6 percent in May from April, the 15th straight month-over-month increase.

Steady hiring and low mortgage rates have encouraged more Americans to buy homes. Greater demand, a limited number of homes for sale and fewer foreclosures have pushed prices higher. Prices are still 20 percent below the peak reached in April 2006, according to CoreLogic.

One worry is that higher mortgage rates could slow the housing recovery. Still, rates remain low by historical standards. And increases in rates could boost home sales, as many Americans may act to lock in the lower rates before they rise further, analysts say.