Thousands of trans-Tasman passengers had their travel plans thrown into disarray by a dust storm on Wednesday, which blanketed the eastern coast of New South Wales before moving north to Queensland.
About 1500 travellers to and from New Zealand were delayed by the massive storm which covered parts of Australia in red dust.
The region's worst dust storm in nearly 70 years shut down outback towns and caused Sydney's sky to glow red, making the air hazardous and disrupting transport.
Winds of up to 100km/h carried soil from inland New South Wales across the state to hang in the sky over Australia's largest city.
The New South Wales Fire Service says it attended more than 600 smoke alarm callouts and people with respiratory problems were advised to stay indoors.
Three Air New Zealand flights bound for Sydney had to return to New Zealand in the morning, as planes were unable to land due to poor visibility. Three flights from Sydney to New Zealand were cancelled.
Air New Zealand used a larger 747 plane to help clear the backlog of waiting travellers on Wednesday afternoon.
The storm also delayed an afternoon service from Christchurch, with about 300 passengers on a Pacific Blue service affected. Jetstar said all its passengers were able to reach their destination, but with delays of up to three hours.
Qantas flights from New Zealand to Sydney were diverted to Melbourne or Brisbane.
Sydney resident Josie Nagel, who returned to Wellington on Wednesday afternoon, told Radio New Zealand she spent a frustrating day watching her flight being cancelled and uncancelled three times.
Ms Nagel said when her flight left she was scared it would not get off the ground and the clouds beneath the plane remained red until half-way across the Tasman Sea.
In Australia, flights were cancelled or delayed in Sydney and Brisbane as the dust storm moved to Queensland. Passengers were facing delays of up to six hours for international flights on Wednesday.
Heavy rain, snow forecast for NZ
The weather system that created the dust storm is expected to bring heavy rain and snow to New Zealand on Thursday.
MetService says it expects up to 80 millimetres of rain to fall in the central North Island from 8am.
It is forecasting a southerly front travelling up the South Island will bring dumps of heavy rain or heavy snow between Taihape and North Canterbury, with the biggest falls in the Tararua Ranges, north of Wellington.
Severe weather batters Australia
The Australian weather bureau says it expects the dust storm will continue to move into Queensland's far north, leaving Sydney and Brisbane with clean air but coated in a film of dust, according to the ABC website.
It has been a difficult 24 hours for Australia, which has been hit by earthquakes, hail storms and bushfires.
In parts of New South Wales, huge hail stones whipped up by thunderstorms smashed windows and sent residents running for cover, the BBC reports.
Further north in Queensland, officials banned open fires in many areas when bushfires sprang up after a spell of hot, dry weather.
Two minor earthquakes hit Victoria state on Tuesday, and heavy rains that followed led officials to issue a warning of flash floods.
