New Zealand's population growth from migration set a new all time high of 55,121 people in the year to February, well up on the gain of 29,022 in the year to February 2014.

February was the seventh straight month in a row that the annual record for population gain from migration has been surpassed.

And the month of February also set a new record, with the population increasing by 7101 during the month, the highest gain in any single month since published records began in 1978.

That's equivalent to the country gaining a new town the size of Wanaka every month.

There were 11,985 people who arrived in the country on a permanent or long term basis (a year or more) in February, while 4884 departed long term, leaving a net gain of 7101.

In the year to February there were 112,614 permanent and long term arrivals and 57,493 departures, giving the net gain of 55,121.

The net gain in population is being driven by growth in the number of new arrivals and declining numbers of people leaving, however the growth in arrivals is now having a bigger impact than the reduction in people leaving.

In the year to February, the number of new arrivals increased by 15,762 compared with the previous year, while the number of departures decreased by 10,337 over the same period.

The biggest net gain (arrivals minus departures) in migrants came from India (11,786 in the year to February), followed by China (7478 plus 634 from Hong Kong), the UK (5051) and the Philippines (3786).

There was a net loss of 2562 people to Australia in the year to February, but that was the smallest annual net loss of population to Australia since the year to March 1992, Statistics NZ said.

Westpac senior economist Felix Delbruck said net migration gains had probably reached a peak, but would likely keep delivering population growth of around 5000 people a month for some time yet.

"Accordingly we remain comfortable in our view that annual net migration will approach a peak of 60,000 towards the end of the year and remain high into 2016," he said.

There was a net loss of 6649 New Zealand citizens in the year to February and a net gain of 61,770 citizens from other countries.