Weather forecast: Rain at last for parched South Island, but dry until Christmas elsewhere

Heavy rain is expected in parts of the South Island today. File photo

Parched areas of the South Island are finally in for heavy rain today as a cold front moves north over New Zealand.

The MetService is forecasting heavy rain of 60-70mm in Fiordland between 6am and 4pm today and about 40mm in Dunedin and North Otago between noon and 11pm.

But only showers are expected over the rest of the country, with some heavy showers on the Coromandel Peninsula, as the front moves north and weakens.

Very light rain of 1-2mm was recorded at Auckland Airport overnight.

MetService forecaster Josh Griffin said the outlook was still drier than usual.

"It looks like we are going to stay relatively dry in the leadup to Christmas, then a return to more normal rainfall after that," he said.

Temperatures have also been higher than usual, with maximums forecast today including 30C in Christchurch, 26 in Auckland and 24 in Wellington.

But the cold front will bring a big drop to 19C tomorrow in Christchurch and Wellington, although Auckland will remain warm at 25C.

"Today is going to be a bit warmer than average for this time of year, returning to average tomorrow," Griffin said.