Australia's property market is enduring a serious winter chill.

Preliminary auction clearance rates in Sydney dropped below 50 per cent last weekend according to Domain's numbers and were clinging just above according to CoreLogic.

Melbourne's market is a little stronger, although still stuck in the 50s.

But many agents are slow to report unsuccessful auctions, so those clearance rates tend to drop noticeably when the final figures come in at the end of the week.

"We're tipping somewhere between 41 and 44 per cent for Sydney and for Melbourne we're thinking it's going to come in roughly around 49 per cent," SQM Research managing director, Louis Christopher, said.

That is a level consistent with the moderate price falls Sydney has experienced over the past year and with the rapid slowdown in the Melbourne market, as prices switch from rising to falling.

Buyer's agent Pete Wargent from Allen Wargent said there is a confluence of factors explaining why properties are not selling at auction.

"A number of different factors have driven it — tighter lending standards, an ongoing royal commission and slower mortgage processing time," he said.

Mr Wargent said a lack of enthusiastic buyers had also made sellers cautious.

"The number of new listings, particularly in Sydney is at the lowest level we've seen in about half a decade, so obviously vendors are not as confident as they have been over the last year or two," he said.

"But, that said, the total number of listings is also at multi-year highs, so that just reflects that the properties that have been listed on the market are taking much longer to sell now than they have been in recent years."

Market will be 'in some trouble' come spring

Instinctively, most people think property markets will be weaker in winter, but Mr Christopher said clearance rates usually get worse in spring.

"It is going to be a very tough spring for sellers," he said.

"Seasonally, we see more listings come on in springtime — lots of vendors think it's a great time to sell, the problem is every vendor kind of thinks that.

"So auction clearance rates seasonally fall in spring for most years."

Based on previous experience, Mr Christopher is expecting auction clearance rates to fall into the 30s for Sydney and mid-40s for Melbourne.

"There's only been about two or three times I've seen auction clearance rates in the 30s," he said.

"That was previously in 2008, when we were entering into the GFC.

"Before that, briefly in 2004 in Sydney when the state had the vendor stamp duty introduced.

"And then, prior to that, back in 1989 when the cash rate hit 17 per cent.

"So, if it does happen, it's a very rare occasion and it will mean the market is in some trouble."

Mr Christopher said auction clearance rates in the 30s would be consistent with annual price falls of at least 5 per cent.

'Patchy' east coast markets see quality properties sell, others stall

Even with auction clearance rates over the past year ranging from the 60s down to the 40s, the Sydney market has already fallen around 5 per cent from its peak last year.

Although both Louis Christopher and Pete Wargent observed that these falls have not been evenly spread, with some properties faring much worse and some holding their value.

"Some of the second tier and secondary quality properties the clearance rates have dropped very sharply," Mr Wargent noted.

He said selling agents needed to offer their clients guidance about realistic price expectations.

"That's where a good agent doing their job should be able to help a vendor set their expectations accordingly," he said, noting unrealistic boom-time expectations are one of the reasons many properties are staying on the market for months.

Outside of Sydney and Melbourne, Mr Wargent is active in the Brisbane market, where he said demand is also "patchy", with high quality properties for upgraders and those moving from the southern states doing well, while other properties struggle to sell.