Warmer than average temperatures are expected throughout September for the top of the North Island but the rest of the country is in for a cooler month.

Lower than usual pressures were expected in September, said MetService meteorologist Georgina Griffiths.

"At the start of the month the low lies over the north of the country, keeping it on the damp and warm side from Taupo northwards, while the South Island keeps most of the dry weather and high pressure," she said.

"But as we move further into the month, expect those lows to shuffle south towards the Cook Strait, bringing rain for the remainder of the North Island," she said.


As a result of those lows, a wetter than normal September was forecast for these places, she said.

However, above average temperatures could be expected north of Taupo.

Although Southland and Otago could expect a drier month, the cool weather would remain, said Ms Griffiths.

August got off to a wet start for the west and far south of the South Island, and the western and central North Island, said Ms Griffiths.

"The second half of the month saw higher pressures over the South Island, with mostly dry conditions seen there," she said.

Heavy rain hit the northeast of the North Island towards the end of August, and caused flash flooding near Rotorua and also around KeriKeri and Kaeo.

She said more cold weather was expected for the end of August, with rain forecast for eastern parts of Northland, Auckland, Coromandel and Bay of Plenty over the weekend.

Compared to the average September:
Auckland: Warmer and wetter
Hamilton: Wetter, near average temperatures
Tauranga: Warmer and wetter
Wellington: Cooler, a little wetter
Christchurch: Cooler
Dunedin: Cooler and drier