Something unusual has happened to house prices in the past four weeks: the average price of mainland capital city homes has risen, at a time when sellers are usually rushing to offload their properties ahead of the summer holiday break.

The pattern suggests the high-flying housing market still has a fair bit of momentum, at least for the time being.

Prices are up by 1.1 per cent from four weeks earlier, according to data updated on Monday by market analytics firm CoreLogic, after the average price for a mainland state capital home eased back marginally last week.

There was no such rise the same time a year ago, nor the year before, even though the market was in the throes of a sustained boom over that time.

Prices did rise over the matching part of 2013, but only by half the 1.1 per cent gain racked up in the latest four-week stretch.

In retrospect, that late-2013 burst of strength was a sign of things to come.

Since the end of 2013, the average mainland capital city home price has risen by 27 per cent, including rises of 45 per cent in Sydney and 31 per cent in Melbourne.

And the latest against-the-grain rise is even stronger as the national market dominated by the big two urban centres is holding up against the seasonal pattern.

That’s partly because the volume of homes being brought to market is a bit less than this time last year.

The number of auctions in the state and territory capitals rose to 2,950 in the week to Sunday, from 2,897 the week before, but was still down by nearly seven per cent from the corresponding week of last year, when 3,166 homes went under the hammer.

Even so, CoreLogic’s preliminary estimate of last week’s auction clearance rate was 75.6 per cent, well over the 59.5 per cent clearance rate a year before.

The sharply higher clearance rate implies that even with fewer auctions the number of completed sales last week was still up by over 18 per cent from a year ago.

Sooner or later something will be the catalyst for the long-awaited correction in housing prices.

It could be rising interest rates, stagnating rents, growing caution among lenders, regulatory pressure, a jump in unemployment, a clamp on immigration, an oversupply of newly built apartments, or more likely a combination of many of those things.

When it happens it could be ugly.

But it’s not happening yet.