All the mountains in the Barrier Mountain range and through the Hollyford Valley, including the Pembroke Glacier in Milford, were stained muddy beige from the bushfires.

New Zealand's iconic white glaciers are turning shades of brown as a result of the smoke that has travelled to New Zealand from the bushfires in New South Wales and Victoria.

Social media posts from tourists and helicopter services in the last 48 hours have shown the wide impact on some of New Zealand's most popular tourist attractions.

"We had already been in tears over the situation in Mallacoota earlier in the day so we were already pretty wrecked emotionally," Rey, an Australian who lives in Wellington, told Stuff.

Rey (via Twitter) The "caramelised" snow at Franz Josef is caused by smoke from the Australian bushfires.

Rey, who did not want her last name published, was near Franz Josef Glacier on Wednesday and snapped photos of the "caramelised" snow, which went viral on social media.

Rey (via Twitter) Another shot taken on January 1 of the beige-coloured snow near Franz Josef glacier.

"In the face of the drastic evidence of the glacial retreat, the tainted snow felt like just one more horror perpetrated by human beings against the planet," she said.

An environmental consultant from Tonkin and Taylor noticed the snow on the Barrier Mountain range had turned brown while they were flying over it on Tuesday.

Satellite imagery courtesy of JM Satellite imagery showing smoke from Australia's bushfires over New Zealand at 2.30pm on Thursday.

"We flew over the Barrier Mountain range and down through the Hollyford Valley and all the mountains, including the Pembroke Glacier in Milford, [were] stained muddy beige from the bushfires," they said.

Mount Cook helicopters lead based pilot Andrew Gutsell said he had been flying around glaciers for the past 13 years and had never seen smoke as bad as it had been over the last couple days.

"It happens every couple of years with the westerly flow that comes over, but this is certainly the worst I've seen by far," he said.

AP An aerial scene shows fires burning and smoke rising close to properties in Bundoora, Victoria state, December 30, 2019.

In satellite notes issued on Thursday morning, Australia's Bureau of Meteorology said "extensive smoke haze" had been seen across eastern New South wales and Victoria "and extends both northwards to Queensland and also extends from the north Central Coast of NSW across the Tasman Sea".

The haze is associated with a surface trough and cold front, the bureau said.

"We can actually smell the burning here in Christchurch," one Twitter user wrote on Wednesday.

She posted a video showing thick smoke over the Tasman Glacier in Aoraki/Mount Cook National Park.

This the view from the top of the Tasman Glacier NZ today - whole South island experiencing bushfire clouds. We can actually smell the burning here in Christchurch. Thinking of you guys. 😢#nswbushfire #AustralianFires #AustraliaBurning pic.twitter.com/iCzOGkou4o — Miss Roho (@MissRoho) January 1, 2020

MetService meteorologist Tahlia Crabtree said a southwesterly flow, which was expected to last into the weekend, was clearing the smoke away from the South Island on Thursday, but there was a chance the winds could change bring more bands of bushfire smoke in the coming days.

Jessie Moffatt Akaroa on January 1 as the smoke haze from Australia covered the sky.