Chances of a warm, dry summer under El Nino conditions are increasing, but Niwa National Climate Centre scientists have warned Kiwis not to get their togs and towels out just yet.
A Niwa report shows the consensus from international models is for the tropical Pacific to transition towards El Nino over the next three months.
However, the upcoming event, should it come to fruition, is not expected to be of a similar intensity or type to what was experienced during 2015-16, 1997-98, or 1982-83.
"The probability for El Nino conditions being established remains high until autumn 2019, with a 71% chance for El Nino conditions over the April-June 2019 period," the report said.
The October-December atmospheric circulation around New Zealand is forecast to be characterised by higher pressure than normal to the west and southwest of New Zealand.
This circulation pattern is expected to be associated with anticyclonic conditions over the country, interspersed by episodes of south to southwesterly winds.
"This circulation pattern may be associated with cold nights and mornings, as well as the potential for late-season frosts and fog, particularly during the month of October."
In Southland and Otago, temperatures are most likely to be near average; and rainfall totals, soil moisture levels and river flows are "about equally likely" to be below normal or near normal.