On a month-on-month basis, Auckland's median price increased by 1.2 per cent or by $10,000, REINZ said.
Six regions had experienced double-digit median price increases in September year-on-year: Tasman up 19.3 per cent to $572,500, Hawke's Bay up 18.3 per cent to $392,000, Gisborne up 14.9 per cent to $270,000, Northland up 14.4 per cent to $446,000, Wellington up 10.6 per cent to $531,000 and Southland up 10 per cent to $220,000.
West Coast prices fell 15.6 per cent to $208,500 and Canterbury was down 3.2 per cent to $426,000, REINZ said, comparing last month to September last year.
National sales volumes for September fell 26.2 per cent year-on-year from 7352 to 5428, the lowest September in six years. Nationally, excluding Auckland, volumes decreased by 23.7 per cent year-on-year.
On Tuesday, what has been seen to be a flat housing market was cited as encouraging New Zealanders to shut their wallets. Statistics NZ's electronic cards data was flat last month and an economist said that was due to cooling house prices.
"Consumer spending has cooled significantly in recent months - in fact, the level of card spending is down since the start of the year," said Westpac chief economist Michael Gordon.
"Consumer spending in New Zealand tends to have a strong link with the housing market, and the slowdown in spending is consistent with the cooling in house prices over the last year. In the absence of a renewed fall in interest rates, we expect the housing market, and therefore growth in consumer spending, to remain subdued over the next couple of years."
Last Wednesday, Quotable Value showed Auckland's housing market had stalled in the past three months with values falling by 0.6 per cent and buyers unable to get finance being blamed. The QV House Price Index showed the city's property values rose a meagre 0.8 per cent in the 12 months to September 2017, the slowest pace of annual growth since April 2011. Despite the drop, the average current value now stands at $1,039,066, putting most houses out of the reach of first-home buyers.
But a day later, Barfoot & Thompson's September data showed a $40,000 leap in price. Barfoot's average sale price was $928,213 last month, up from $918,926 in August, and the median rose by $40,000 to $860,000.
The conflicting data was because QV captured all Auckland values, based on sales over a three-month period, whereas the Barfoot sales figures are from only one agency and only for a month.