Rainfall is likely to be near normal, while soil moisture levels and river flows are likely to be below normal.
Similar conditions are likely for the rest of the North Island, except for soil moisture levels, which are likely to be near or below normal.
In the South Island, temperatures over the next few months are very likely to be above average.
River flows and soil moisture levels are likely to be below or near normal, except for the north of the South Island, where river flows are likely to be below normal.
Niwa said the equatorial Pacific Ocean was likely to remain in a neutral state, with neither El Nino nor La Nina conditions over the next three months.
Higher pressures are likely to prevail over the South Island and further south over the next few months.
The tropical cyclone season has one more month to go, but the risk of an ex-cyclone approaching New Zealand remains near normal.
An average of one ex-cyclone nears the country during cyclone season, which runs from November through April.