A nasty front is quickly making its way up the country, bringing heavy rain and possible thunderstorms along with gale-force winds.
MetService meteorologist Andy Best said coastal parts of Canterbury will bear the brunt of the front's southwesterlies. Southland, Clutha and Fiordland will all receive heavy rain before it hits Oamaru about midday.
Best warns tourists and locals to take shelter around Lyttleton and Akaroa.
The West Coast will be lashed with rain before it eventually eases this evening.
It will hit the lower North Island, Levin and then New Plymouth, about midnight. Wellington will cool down markedly as the winds whip through.
There is a chance of thunderstorms around Manawatu and Horowhenua tonight.
The front weakens as it moves north. Scattered rain hits central North Island and by the time it hits Hamilton then Auckland tomorrow morning it will be scaled down to isolated showers. Auckland will clear to a fine afternoon.
It's unclear if it will have the same impact as heavy rain that hit some North Island centres last night. Rotorua received 34.2mm of rain between 6pm and 7pm, and Pongakawa in the Bay of Plenty got 23mm.
Tauranga Airport received 14.4mm but quite a few downpours around the city weren't recorded by a rain gauge, where between 50mm and 70mm of rain fell.
After the front sweeps up the country, it makes way for a ridge of high pressure, which is then taken over by another brief front bringing more rain and wind.
Meanwhile, Niwa has released its Christmas Day forecast for the main centres:
Auckland: Partly sunny. 24C.
Tauranga: Mostly cloudy. 23C.
Hamilton: Mostly cloudy with afternoon showers possible. 23C.
Wellington: Partly sunny and breezy. Chance of showers. 20C.
Christchurch: Increasing cloud with possible showers in evening. Windy and warm. 27C.
Dunedin: Windy with rain developing. 22C before dropping in afternoon.
