Last year was another record-setter in real estate.

The median sale price of a single-family home in Massachusetts hit $385,000, a record high and up 5.5 percent from 2017, according to data from The Warren Group, a real estate data and analytics firm.

In 2018, the median price of a single-family home in Worcester County was $275,000. That's a 6.2 percent increase from 2017, when it was $259,000. The median price of a condo in Worcester County was $205,000, a 2.5 percent increase from 2017, when it was $199,900.

Overall, sales dipped slightly in 2018, due to a historically low inventory of homes for sale. Worcester County home sales were down 1.4 percent and condo sales were down 3.3 percent.

In the city of Worcester, the median single-family home price rose 6.5 percent to $238,000. The median condominium price rose 6.7 percent to $144,000 in 2018.

In Auburn, the median single-family home price rose 13.1 percent to $267,5,000, but the median condominium price dropped 3 percent to $177,450 in 2018.

The median single-family home price also jumped in Holden, up 14 percent to $324,900, and the median condo price was up 17.9 percent to $230,000.

In Shrewsbury, the median single-family home price was up 4.4 percent to $417,750, and the median condominium price rose 6.6 percent to $302,500 in 2018.

Experts believe Worcester County is outpacing the state for several reasons, and those factors are not going to change any time soon.

Cassidy Murphy, associate publisher and media relations director for The Warren Group, said when her company looked at the data to see which communities were driving the statewide price gains, they were surprised to find it wasn’t the tony Boston suburbs many people would have suspected.

“It’s not communities like Dover, Wellesley, Lexington and Concord,” Ms. Murphy said. “I think prices in those communities have plateaued. It’s places like Worcester County and along the northern and western borders. Places that were slower to recover from the recession and are seen as an affordable alternative to Greater Boston’s high prices.”

Anthony Lamacchia, owner of Waltham-based Lamacchia Realty opened an office in Worcester in 2016. He said many buyers see more value in Worcester and the ongoing dramatic improvements to the downtown are only going to draw more people and keep them here.

“It’s clear to me as a relative newcomer to the Worcester market that it is on the rise,” Mr. Lamacchia said. “It’s the second largest city in New England and there’s a great supply of good homes there. I’m very impressed with what’s going on across the city, like the PawSox relocating there and the Railers. The fundamentals are strong and the buyers are there.”

Tracey Fiorelli, of Janice Mitchell Real Estate in Holden, is the 2019 president of the Central Mass. Association of Realtors. She said Worcester’s surging renaissance is a big part of the price growth, but historically low inventory of homes for sale is both driving home prices up and pushing more would-be home buyers into the less expensive condo market, pushing those prices up as well.

“Single-family home inventory is at an all time low," Ms. Fiorelli said. “That pushes prices up and shifts more buyers into the condo market. The hope is that will improve in 2019. We’re working hard to pass legislation to allow for more housing production. But 2019 is predicted to mirror 2018. It makes it very difficult for first time home buyers.”

Ms. Fiorelli said the winter has been atypically busy, which is a good sign for sellers and a bad one for buyers.

“It’s busy in the sense that houses are selling quickly at good prices,” Ms. Fiorelli said. “When a house comes on, buyers line up and you get multiple offers in hot communities like Holden, Auburn, Worcester. Recently, there were two houses that came on the market at the same time around $250,000. There were open houses, there were multiple offers, and there was a bidding war.”

After trending steadily downward for months, the inventory of homes for sale ticked upward at the end of 2018, which is a good sign for buyers and agents seeking to return to a more balanced market. But it’s too soon to say if that’s an aberration or the beginning of a new trend.

Ms. Murphy said so many factors go into a seller’s decision to put their house on the market, it’s hard to predict when inventory will increase enough to balance the market — or increase at all.

“When inventory went up in the fall it caught everyone by surprise,” Ms. Murphy said. “The federal government has been shut down for more than a month now and it’s starting to have an effect on our economy. If inventory does increase in 2019, my guess is it will only open up a little.”