During the March, April and May quarter the estimated value of houses went up by 11.3 per cent - the second biggest growth nationally for that time period, behind Hastings at 11.4 per cent.
Wilson said now that Whanganui was at level 3, people could expect activity in the market to start to climb quickly.
"We're expecting to see what I'd call a mini-surge of activity across buyer groups, probably led by investors.''
He said buyers would want to make a move on a house they may have been thinking about before lockdown started.
That would be driven by fear of future lockdowns and a looming increase in interest rates, Wilson said.
"Expect a wee bit of a return to that kind of crazy hype conditions for a period of time.
"It's fair to conclude that we probably won't see it continue for as long as we did this time a year ago, just because of where New Zealand and the world is at with their Covid story and where interest rates might go in New Zealand in the next couple of quarters."
In July, OneRoof released its median sale prices - different to the average values - which had Whanganui at $454,000.
The house value index was calculated by Valocity, and was designed to measure what was happening in the market right now, Wilson said.
"The methodology used allows us to incorporate a wide range of property data sources and ingest sales quickly after they are made."
The index showed nationally that while prices had still been climbing, the level of growth "has come off the accelerator" compared to the three months to the end of May.
The average house value in New Zealand was sitting at $983,000, close to breaking the $1 million mark.
Of the regions, Waikato saw the biggest jump in prices compared to the end of May, with its average property value up 6.1 per cent, from $821,000 to $871,000.
Also showing strong growth were Canterbury (up 5.5 per cent to $668,000), Bay of Plenty (up 5.5 per cent to $945,000), Tasman (up 5.3 per cent to $913,000), and Gisborne (up 5.1 per cent to $664,000).
Southland was the weakest performer, recording growth of just 2.6 per cent over the quarter for a new average property value of $472,000.
West Coast remains the cheapest region for real estate, with its average value sitting at $350,000, although a lift in market activity has seen it turn in growth of 4.5 per cent since May.
The Auckland and Wellington regions remained the most expensive for property, with quarterly growth of around 4.5 per cent pushing their average property value to $1.395 million and $1.037 million respectively.
Across the country, investors' share of new mortgage registrations in the three months to the end of August was 24 per cent, down from 27 per cent in the previous quarter, while first-home buyers increased their share slightly from 36 per cent to 39 per cent over the same period.
