Asking prices for homes have trended upwards by nearly 10%, according to the Trulia Price Monitor, with some metro areas seeing double-digit price jumps.

The month of May saw asking prices rise in 98 out of the 100 largest metros, with national prices continuing their steady increase to a 9.5% year-over-year growth, says Trulia.  

Seasonally adjusted, prices rose 4% from May 2012, and were up 1.1% from the previous month. 

Out of the 10 least affordable markets tracked by Trulia, eight showed double-digit asking price increases. Seven of those are located in California, including Orange County, Oakland, and San Jose—all of which had price increases of more than 20%.

“Home prices are rising fastest in the local markets that were least affordable to begin with,” said Jed Kolko, Trulia’s Chief Economist, in a statement. “As the gap between the most and least affordable markets widens, more people in expensive markets like California will look to relocate to cheaper markets like Texas when the time comes to buy.”

Across the 10 least affordable housing markets, prices were up 16.3% on average, ranging from Long Island, N.Y. on the low end with a 1.1% increase to Oakland, Calif., where asking prices shot up 31.2%. 

Other markets on Trulia’s “least affordable” list include Honolulu, Hawaii, up 12.8% year-over-year, and San Francisco, up 19.6%. 

Trulia measures affordability  in terms of a 30-year mortgage with a 3.8% fixed interest rate on an 1,800-square-foot home at the local median asking price per foot, divided by the local average monthly wage for a worker. 

Written by Alyssa Gerace