The numbers: The pace of home-price appreciation once again ramped up in January, according to a major price barometer.

The S&P CoreLogic Case-Shiller 20-city price index posted a 3.1% year-over-year gain in January, up from 2.8% the previous month. On a monthly basis, the index increased 0.3% between December and January.

Because of the two-month lag in the data included in the price index, the effects of the coronavirus pandemic on the housing market were not yet reflected in the data.

What happened: Phoenix led the nation once more with a 6.9% annual price gain in January. Close behind were Seattle, Tampa, Fla., and San Diego, where prices rose by 5.1%. In total, 14 of the 20 cities in the index reported higher price increases year-over-year in January versus December.

On a regional basis, home price growth was strong in the West and the South, while comparatively weak in the Midwest and the Northeast, said Craig J. Lazzara, managing director and global head of index investment strategy at S&P Dow Jones Indices.

The big picture: The Federal Housing Finance Agency released its own monthly home-price index last week, which showed a 5.2% year-over-year gain in January. While home-price growth has accelerated in recent months, a year ago the pace of appreciation was actually slightly higher in most regions across the U.S., the FHFA report showed.

As the low supply of homes on the market has been met with high demand, home prices have been pushed higher. Low mortgage rates in recent months have encouraged that trend, because the low rate environment can make higher prices more palatable to buyers who might otherwise find them too expensive.

The question for the market now is whether home prices will take a hit as a result of the coronavirus pandemic. While real-estate economists broadly expect sales volume to plummet, it’s unclear what effect the COVID-19 national health emergency will have on prices. A recent report from Zillow ZG, +1.34% that analyzed what happened to the economy of regions affected by past disease outbreaks suggests that home prices may not fall along with sales.

What they’re saying: “Home prices increased nearly every month in 2019 and continued to push upward in early 2020 with strong demand,” said Bill Banfield, executive vice president of capital markets at Quicken Loans. “It’s yet to be seen how home prices will react through, and after, the current health crisis. I suspect once the stay-at-home orders are lifted, homebuyer demand will regain its footing, provided employment rebounds quickly.”