Among those entering under a visa, the largest category (31,900) had work visas, most of them from Europe or North America. There were 21,400 on student visas, more than a third of them from India, and 13,300 on residence visas.
Nearly half the net migration gain (21,000) was to Auckland.
"While shy of the highs seen in early 2003, the population growth will likely add to already strong housing demand in Auckland," said ASB economist Christina Leung.
Deutsche Bank chief economist Darren Gibbs noted that the annual inflow of all migrants, whether they are classified as short-term or permanent and long-term, was 53,710 in September. "So called 'category-hopping' means that swings in total migrant inflows are typically even larger than suggested by looking solely at self-classified permanent and long-term flows," Gibbs said.
"Stronger-than-expected migrant flows risk reigniting the housing market and remain a key source of upside risk to the Reserve Bank's growth and domestic inflation forecasts," Gibbs said.
"However, to date the bank has been pleasantly surprised at the lack of spillover from recent migrant inflows into the performance of the market for existing homes."
Gibbs said it remained an open question whether the spillover would still happen, but with a lag, or whether it reflected the composition of foreign migrant arrivals - noting the 43 per cent rise in foreign student arrivals over the past year.
"In the first instance students are more likely to place pressures on the rental market."
The numbers
45,400
net gain from migration, year to September
15,000
New Zealanders returning from Australia
6000
net loss to Australia, smallest since 1994