Statistics New Zealand figures released last week showed short-term visitor arrivals had fallen sharply in February and March, following the February earthquake in Christchurch.
However, the disruption to visitor numbers proved temporary and arrivals from most countries recovered in April and May, ASB economist Jane Turner said.
Visitor arrivals in May were less than 1% lower than the levels a year ago.
"Arrivals from Japan and Korea remain low, most likely reflecting the disruption caused by Japan's earthquake in March. According to our own seasonally adjusted estimates, arrivals from Japan fell around 30% in both March and April but have started to stabilise in May.
"Recent visitor arrival figures have been encouraging, suggesting the earthquake impact on national tourism will be limited. But the experience between different regions will likely be substantial."
While national short-term visitor arrival numbers had recovered, accommodation data suggested that many tourists were avoiding the South Island following the February quake, Ms Turner said.
In addition, the high level of the New Zealand dollar against most other major currencies - with the exception of Australia - was a further impediment to the tourism sector.
The warmer weather and late start to the ski season was likely to weigh on arrival numbers in June and July. The Rugby World Cup should start to boost visitor numbers from August, she said.
Statistics NZ figures also showed that New Zealanders continued to permanently leave the country, with a net migration loss for a third consecutive month.
The net outflow of 3300 migrants to Australia in May was up from 1700 in May last year and higher than the previous May month net outflow of 2900 in 1979.
On a seasonally adjusted basis, a net outflow of 400 migrants was recorded in May.
Numbers leaving had been higher than those arriving since March, when there was a rise in departures from Christchurch following the February quake.
Unadjusted, permanent and long-term (PLT) departures outnumbered arrivals by 2100 last month, compared with 1300 more departures than arrivals in May 2010.
PLT departures of Christchurch residents rose to 800 in May, up from 500 in May last year, while PLT arrivals in the city fell from 400 to 300 in the same period.
