Single-family home sales in Massachusetts this January were up 25 percent and condominium sales were up 29 percent over January 2015, according to data from the Warren Group, publisher of Banker & Tradesman.

Prices, however, dropped slightly. The median single-family home sale price in January was $320,000, down 0.48 percent from $321,550 last January. The median condo sale price was down 3 percent to $290,875 from January 2015.

Anthony Lamacchia, owner of Lamacchia Realty, said there are three main factors that explain the large increase in sales year over year. The weather last winter was unusually harsh and stalled homebuying activity and this winter has been mild, which always helps sales, he said.

“A lot of the deals we put together at the end of last year closed in 60 days, instead of 45, because of the new TRID regulations,” Lamacchia said. “So many deals that would have closed at the end of December ended up closing in January instead.”

Lamacchia said the third reason is that this winter has been steadily busy straight through. He said he is starting to see more houses come on the market, but they’re going under agreement at a faster pace than they’re coming on.

“Demand is very strong,” Lamacchia said. “The market is clearly racing.”