Auckland's average house sale price fell by $47,632 between December and January.

Barfoot & Thompson's data yesterday showed December's average $552,933 sale price dropped to $505,301 last month.

Volumes were also down from 648 sales in December to 583.

Managing director Peter Thompson blamed summer holidays and the traditional exodus from the city in warmer weather.

Shamubeel Eaqub, principal economist for the NZ Institute of Economic Research, said once typical seasonal patterns were taken into account, the city's housing market still slowed very sharply in January.

"In particular, sales volumes have plunged and are now similar to early-2009 levels. Also, the weak level of sales means that there is suddenly plenty of homes for sale. There is now nearly nine months' worth of homes listed for sale, similar to the level in early 2009."

Rising mortgage interest rates and a fragile economic backdrop were more to blame than the warm weather, Mr Eaqub said.

The outlook was further clouded by potential tax changes, particularly for residential property investors.

"The outlook for the housing market and the broader economy is uncertain. Renewed weakness in activity against a backdrop of rising unemployment and slowing wages is very worrying. The Reserve Bank is right to wait until mid-2010 to begin raising interest rates," Mr Eaqub said.

Mr Thompson said January was traditionally one of the slowest months but he still believed the year had got off to a good start. He cited 1118 new listings, up 22 per cent in a month.

Barfoot had 5703 properties on its books to sell at the start of this month.

Auckland's average weekly rent last month was $401, up $17 from a year ago.

Auckland property manager Crockers, sourcing figures from the Real Estate Institute and Department of Building and Housing, gave a market update this week showing Auckland's city centre (Parnell, Grafton, Newton) commands $290 a week for one bedroom, $365-$400 for two bedrooms, $500 for three and $635-$650 for four.

These figures compare with the NZ averages of $210-$215, $270-$280, $325-$335 and $400 for each bracket.

House sales 2009-10

* January: $502,636
* February: $512,536
* March: $491,780
* April: $502,726
* May: $533,909
* June: $521,791
* July: $507,384
* August: $532,023
* September: $514,890
* October: $544,769
* November: $550,217
* December: $552,933
* January: $505,301

Source: Barfoot & Thompson, monthly