Qantas cancelled all flights in and out of Canberra Airport on Sunday as the capital was blanketed in an orange haze from raging bushfires.
Some flights were diverted to Sydney.
Virgin Australia also had some flight disruptions in Canberra. Singapore Airlines was operating in and out of the airport.
One diverted Qantas passenger tweeted: "We’re stranded and unwilling to drive from Sydney to Canberra with changing conditions along the highway."
There were few people on the streets of Canberra on Sunday with dozens of businesses closed along with landmarks and attractions including the National Gallery of Australia and the National Portrait Gallery.
Dozens of nature reserves, conservation areas and campgrounds close to the city have been closed through Monday.
The air quality index in the CBD was close to 3,000.
Anything above 200 is considered a health hazard.
The Bureau of Meteorology says it expects the heavy smoke-filled air to stay for several days.
This is all despite there being no fires within 60km of downtown.
Canberra’s air quality was the worst of any major city in the world at midday on Sunday.
Chief minister Andrew Barr said 100,000 face masks are being handed out to residents.
Meanwhile the thick smoke, with the aid of strong winds, has made its way all the way over the Tasman Sea to New Zealand.
A bright orange haze also enveloped Auckland even though the city is more than 2,000 km from the bush fires.
