Home values are setting new records, and homes are gaining thousands of dollars in value every month. The national median home value is $12,500 more than it was just one year ago, according to the October Zillow Real Estate Market Report.

More than half of the nation's largest markets are worth more than they were prior to the onset of the Great Recession. Home values in San Jose, Calif. gained the most in value over the last year, with homes worth 12.3 percent more than they were in October 2016, which translates to a $118,200 increase. Seattle – 11.7 percent – and Las Vegas – 11.2 percent – also saw double-digit home value appreciation over the past year.

Limited housing supply and heavy demand continue to play a role in driving up home prices. There are 11.7 percent fewer homes for sale in the U.S. than a year ago. Inventory has dropped most significantly in San Jose, San Francisco and San Diego over the past year. In San Jose, there are 60.4 percent fewer homes on the market than at this time last year. In San Francisco and San Diego there are 32 and 31 percent fewer homes fewer homes for sale, respectively.

"We are in the midst of an inventory crisis that shows no signs of waning, impacting potential buyers all across the country," said Zillow Chief Economist Dr. Svenja Gudell. "Home values are growing at a historically fast pace, and those potential buyers want to get in the market while they still can. But with homes gaining so much value in just one year, buyers – especially first-time buyers – have to set aside more and more money for a down payment just to keep up with them. Unfortunately, there's just not enough homes for sale, and demand will continue to drive prices higher until we reach a better balance between supply and demand."

Annual rent appreciation grew for the sixth consecutive month, with rents increasing 2.2 percent from last October to a Zillow Rent Index of $1,432.

Mortgage rates on Zillow ended the month of October at 3.73 percent. Rates reached a monthly high of 3.82 percent near the end of the month, and the lowest rate of the month was 3.68 percent. Zillow's real-time mortgage rates are based on thousands of custom mortgage quotes submitted daily to anonymous borrowers on the Zillow Mortgages site and reflect the most recent changes in the market.