Fire crews are fighting up to seven scrub fires across the South Island.

Fire and Emergency (FENZ) mid-south Canterbury district manager Rob Hands said crews were at fires in Hurunui, Waipara, Springfield, Selwyn, the Mackenzie Country and Shannon, near Dunedin, on Saturday afternoon.

"The most significant [fire] probably is Amberley where we have had to evacuate five houses," he said.

"[We] have lost a couple of buildings and a caravan."

Residents were being evacuated from Racecourse Road, east of Mt Brown Road, due to a vegetation fire.

Those on Rubicon Road just south of Midland Road in Springfield should prepare to leave also, FENZ said. Police would advise them if they needed to evacuate.

An evacuation centre was being set up in the Amberley Domain, said Hands.

The fire at Lake Tekapo currently extended over 150 hectares and about 30 firefighters were on site.

"I haven't had confirmation about the others, but the fact that they've been going for an hour or so, I imagine they've all been getting large," he said.

One house in Waipara had been evacuated.

Hands urged South Islanders not to burn outdoor fires in the high winds.

"Please wait until the strong wind forecast has receded.

"Anyone that has had a fire in the last two or three days, please go and check it and ensure that it is out."

Hurunui Mayor Marie Black said the weather was affecting the work of their volunteer brigades.

"My message to everybody is to stay away from these sites, let our volunteers do their work."

MetService earlier on Saturday warned of "severe gale west to northwesterlies" for southern parts of the country.

Strong wind watches were in force for Inland Canterbury Plains, Queenstown Lakes District, Central Otago, Stewart Island and coastal parts of mainland Southland, Clutha and Dunedin, as well as southern parts of the North Island.

"A front over the south of the South Island continues to move northeast. The front is bringing a period of heavy rain to Westland, and severe gale west to northwesterlies to parts of central and southern New Zealand.

"Watches and warnings for heavy rain and severe gales are in force. People are advised to keep up to date with the latest forecasts and check for areas being added or upgraded."