Hundreds of tourists are stranded on the West Coast, and on the other side of the South Island a flood-damaged bridge has closed State Highway 1, after a weekend of torrential rain.

The heavy rain battered much of the West Coast causing major slips on a 350 kilometre stretch of State Highway 6 between Hokitika and Haast, and most of the 970 tourists trapped in Franz Josef might have to remain there until Friday.

Major roads are closed on both sides of the South Island. Timaru District remains in a state of emergency with road access north to Christchurch blocked with the two bridges crossing the Rangitata River closed. Hundred of tourists were left scrambling to find accommodation in the region.

There were a total of 3309 lightning strikes recorded in the North Island between 6pm yesterday and 6am today, the MetService said.

The most rain fell in the ranges of eastern Bay of Plenty in that 12-hour period - 55.4mm.
The next heaviest rainfalls were recorded in Whitianga, where 20.8mm of rain fell during that time and 20.2mm in Rotorua.

Despite the gloomy weather over the past couple of days, MetService meteorologist Amy Rossiter said most people could expect a mostly fine day to start off the working week.

A front that was causing the wild weather had mostly cleared, she said, and was now sitting offshore and could still affect parts of eastern Bay of Plenty and Gisborne this morning.

"Most of the country should be fine," she said.

There will be a few light and isolated showers in some parts, she said, but the mostly fine conditions would be a welcome reprieve to those who were in for a huge clean-up, in particular.

The earliest most of the 970 tourists trapped in Franz Josef are likely to get out is Friday, while in the Timaru District, the council says it could take weeks to recover from damage caused by floods.

Townships on the West Coast, including Franz Josef and Fox, are cut off after washouts and slips blocked State Highway 6.

On the other side of the South Island, the flood-damaged Rangitata Bridge, on SH1, and the bridge at Arundel, on SH72, are closed.

Timaru District Council duty controller Justin Bagust said road crews had been working through the night and the bridges would be inspected this morning to check when they may be able to reopen soon.

"It's the second largest time that we've ever had this much water come down the Rangitata in 40 years," he said.

"So there is as much water in the river as there is out of the river - so quite extensive break-outs and flooding alongside of that south branch."

An update from the council is expected about 8am.

Timaru District remains under a state of emergency. It will not be lifted until at least one of the bridges reopens, authorities said.

The washouts and slips south and north of Franz Josef mean the only way anyone can get in or out is by helicopter.

Up to 45 dairy farms just north of Franz Josef - at Whataroa - are also cut off and will start dumping milk today because no tankers have been able to get through since late last week.

Civil defence co-ordinator in the area, Wayne Costello, said the best hope of reconnecting Whataroa and Franz Josef with the rest of the country is to repair the road to the south - something road crews are hoping to get done by the end of the working week.

He said it was now a case of flying in enough food for those who are trapped in the town this week.

A portion of a slip-hit West Coast highway could be reopened after authorities assess it this morning.

SH6 from Hokitika to Franz Josef has been closed since Saturday after a large slip at Mt Hercules south of Harihari.

Westland District Council Emergency Control Centre spokeswoman, Kim Hibbs, said SH6 between Hokitika and Harihari may reopen after it is reassessed.

Further south, the highway from Harihari and Mt Hercules is likely to be closed until at least Friday.

Meanwhile a generator is due to arrive in Fox Glacier by midday today where power has been out since Saturday.

A convoy of about 400 tourists was led out of the town yesterday.

Civil Defence Minister Peeni Henare and the Director of Civil Defence Sarah Black-Stuart will be on the West Coast today assessing the impact of the slips.

Henare said the Ministry of Foreign Affairs is supporting foreign tourists stranded by the slips.