The county's median sale price was $109,000 last month, rising 12 percent from $97,300 in May 2011, according to Home Encounter, a Tampa-based real estate consulting firm. Polk's median was $104,900 in April.

A total 461 existing home sales were recorded by local Realtor associations in May, up from 403 a year ago and unchanged from April.

Renee Butler, owner of Winter Haven-based Brokers Realty of Central Florida, said the firm's closings are up more than 30 percent this year compared to 2011. A tightening supply of existing homes and rising prices appear to be spurring many home shoppers, Butler said.

"It's looking extremely well," she said. "Typically right now I'm working with educated buyers — people who have done their research (and see market conditions changing)."

Statewide, sales of existing single-family homes were up 7.2 percent from May 2011, according to the Florida Realtors association. The state's median sale price was $147,000, marking an annual increase of 8.9 percent.

In Polk, Lakeland had 245 homes sold in May, inching up 4.3 percent from the year before. East Polk recorded 197 homes sold for a 30 percent annual jump.

Lake Wales had 12 homes sold, two fewer than the year prior. Seven homes were sold in Bartow, compared with three in May 2011.

Conventional (non-distressed) homes accounted for about 51 percent of Polk sales in May, according to Home Encounter. Foreclosures made up 26 percent of transactions, with short sales accounting for the remainder.