Near-record housing costs are weighing on pending home sales in the US, but there are early signs about a potential pickup in demand, Redfin (RDFN) said Thursday.

The median monthly mortgage payment increased 4.8% year over year to $2,793 during the four-week period ended March 16, the real estate brokerage said. That's just $6 below the all-time high hit in April.

Pending sales fell 5.2% annually during the period, in line with declines over the last two months, according to the Redfin report.

Housing costs increased as sale prices continued to rise and mortgage rates remained elevated. The median home-sale price increased 3.3% year over year during the four-week period to $383,475. The daily average 30-year fixed mortgage rate was 6.76% as of Wednesday, up from 6.7% two weeks earlier but still near the lowest level since December, Redfin said, citing Mortgage News Daily.

"Lack of affordability is suppressing homebuyer demand, even as we get tantalizingly close to spring," the brokerage said. "But there are signals that house hunters are stepping off the sidelines, even if they're not following through with a purchase yet."

The brokerage said its homebuyer demand index, a measure of home tours and other buying services from Redfin agents, hit its highest level in three months in the middle of March and was 5% higher annually.

Meanwhile, as of Tuesday, touring activity increased 35% from the start of the year, the brokerage said, citing data from home touring technology company ShowingTime. In addition, Redfin said seasonally adjusted mortgage-purchase applications hit their highest level in six weeks.

"Rising demand could translate into an improvement in pending sales in the coming months, especially if mortgage rates decline more," the brokerage said. "Rates could decline if inflation eases and we see stronger evidence of weak economic data that point toward a recession."