The 2015 housing market is off to a very strong start, according to Redfin, the customer-first real estate brokerage.

Redfin reports home price data early using its proprietary models and projections based on sales in the first three weeks of the month and from its own brokerage activity.

This month, the median home sale price has fallen just 1.2% from last month, a mere third of the price decline seen a year ago, and the smallest January home-price decline in at least the past seven years, Redfin’s data shows.

January’s median home price is actually up a solid 7.6% year-over-year.

Elements that contributed to this, according to Redfin Chief Economist Nela Richardson, are inventory, increased demand, and growing interest from first-time buyers.

In December, the number of homes for sale increased 4.8% year over year.

December saw a 9.5% increase in new listings, more than any other December since 2008.

Redfin home-tour demand hit an all-time record last week, with the number of customers requesting tours up 62% and signed offers up 58% year over year.

In the first three weeks of the year, the number of customers requesting tours surged 40% and offers shot up 30% year over year.

"Rock-bottom interest rates and easier loans are giving us flashbacks to 2013," Richardson said. "A Redfin agent in Seattle, Klaus Gosma, hosted an open house for an average townhome that was flooded with 132 people over the weekend. In Denver, a house got 23 offers in one, snowy day."

Today’s Real-Time Market Tracker from Redfin also reports on December housing market data, highlighted by 5% year-over-year increases in median sale prices, home sales and inventory.

Looking ahead, Richardson says that conditions heading into 2015 are favorable: buyer demand, low interest rates and more homes for sale. But inventory in a few metro areas is critically low, which could really sink sales volume in those places unless we see a much-anticipated surge in new listings in the next few months.

A clear warning sign on this comes from San Jose. The number of homes for sale was down 35% from November to December, and 8% year over year. The metro area had a 76% month-over-month drop in home sales.

In metro areas like Dallas, Boulder and Portland, the number of homes on the market is down more than 10% from a year ago. Homes in Denver are now selling faster than in the San Francisco Bay Area, which had long been the fastest housing market in the country. Because of low inventory in Denver, half of all listings were off market in less than two weeks (48.1%) and the median days on market was just 16 compared with 43 in all Redfin markets.