The smoke first reached New Zealand's South Island on Tuesday turning skies a hazy yellow. By Thursday, the haze and burnt smell had also reached the North Island.
"I have never seen anything like the haze over the past 48 hours," Arthur McBride of glacier tour company Alpine Guides told the BBC on Thursday.
Tourist flights up to Tasman, Franz Josef and Fox glaciers are a popular way to experience New Zealand's stunning mountain scenery.
But for the past days, visitors have endured a thick yellow haze, instead of the white snow and bright blue skies expected.
"Wednesday afternoon was particularly bad," McBride said, adding: "The smell of woodsmoke is still distinct."
Over the past days, a few trips also had to be cancelled, he said.
Australia and New Zealand are separated by around 2,000 km of the Tasman Sea.
The peaks around the tourist city of Queenstown were also covered in haze.
Over the past days, the people of Dunedin on South Island woke up to a noticeably darker sky, according to local media, and there's been a strong yellowish twilight over the town.
Australia is grappling with bushfire crisis fuelled by record-breaking temperatures and months of drought, the BBC reported.
At least 17 people are confirmed to have been killed by the bushfires, which have burned vast areas of several Australian states, including the worst-hit New South Wales.
Several people were still missing with conditions expected to worsen over the weekend.
( With inputs from IANS )