A robust spring market is causing sellers to up their asking prices, according to a preliminary analysis of May data from realtor.com®.

“The past three months have set new records,” says Jonathan Smoke, realtor.com®’s chief economist. “Prior to that, the highest median list price was July last year.”

The median list price in May is $250,000 – 9 percent higher than a year ago. That also marks the highest median list price since realtor.com® began collecting such data in 2013.

“This spring real estate market is coming in strong, just as we expected,” Smoke says. “Pent-up demand and low mortgage rates are driving consumers into the market with urgency. However, the recurring issue of limited supply is leading to higher prices.”

In May, homes likely will have spent a median of 65 days on the market, which is three days faster than April but about the same length of time as a year ago.

Inventories are increasing, up 4 percent from a month ago. More than 550,000 listings have been added to the market so far in May. Yet, that still is 4 percent lower than it was a year ago.

Realtor.com®’s site traffic this month posted a 30 percent growth in searches for homes for sale compared to a year ago.