Fewer of the southwesterly and westerly weather patterns which have made for an unsettled summer are predicted to affect Otago this autumn, Niwa says.
While Otago battled single figure temperatures, hail and strong southwest winds this week, it is predicted they will happen less frequently in coming months.
Niwa's climate outlook for March to May said mean sea level pressures were expected to be lower than normal to the north of the country, with higher pressures than usual to the southeast.
That circulation pattern was likely to be associated with abnormal weak easterly flows over the South Island.
Climate scientist Brett Mullen said the pattern meant fewer westerly fronts coming through, although as autumn progressed, cold snaps and frosts could be expected from time to time.
''Temperatures will drop as you go into autumn.''
Southwesterlies might still hit Dunedin but they could be weaker than they would have been, he said.
''It'll improve more on the west coast than the east.''
The indications were that Otago would experience near average temperatures and rainfall but below normal soil moisture and river flow levels, he said.
Sea surface temperatures were expected to be near average around New Zealand for the next three months.
''But in the following winter season about half the international models develop El Nino or borderline El Nino conditions,'' he said.
