Single-family home sales in Massachusetts rose by 20.9 percent in May, and the median sale price reached an eight-month high, according to a new report from The Warren Group, publisher of Banker & Tradesman.

There were 5,297 single-family homes sold in the Bay State in May, compared with 4,382 in May 2015. Year-to-date, sales were up by 28.2 percent, with 19,554 homes sold in the first five months of 2016 compared with 15,258 sold during the same time last year.

The median sale price of a single-family home in May was $347,000, a $7,000 increase from $340,000 last year, the highest median sale price in eight months. Year-to-date prices remained flat, with a median sale price of $325,500, up 0.2 percent from the same period in 2015.

“Single-family sales increased pretty dramatically year over year,” said Larry Rideout, owner/CEO of Gibson Sotheby’s International Realty. “The suburbs are catching up now. I’m still cautious about maintaining these incredible numbers. June is going to be off the charts. Then in July, units at the Millennium are going to start closing and you’ll see some big impacts.”

The 60-story luxury condominium tower in Boston’s Downtown Crossing was 90 percent presold at the topping-off ceremony in September of last year; the penthouse went under agreement earlier this month for an estimated $35 million.

Condominium sales rose in May by 9 percent, with 2,146 condos sold compared with 1,969 sold in May 2015. This marked the 12th consecutive month of increases in condo sales. Year-to-date, condo sales increased by 19.4 percent to 7,845 condos sold, compared with 6,573 in the same timeframe last year.

The median condo price in the Bay State increased in May by 4.4 percent to $335,000, compared with $321,000 in the same month last year. Year-to-date, condo prices were up 3.2 percent to a median sale price of $310,000 compared with $300,450 in the same time period last year.

Rideout said he’s also seeing an increase in properties for sale; not enough to flood the market, but enough to bring some balance to what has been a strong seller’s market.

“Things might be reaching a point where the inventory will be at a level where people can make more thoughtful decisions,” Rideout said. “That’s the good news, that we’re supplying demand. It’s better for everyone when the market is balanced. We’re going to see a strong second half. The numbers in June and July are going to choke you. It’s going to be a great year.”