CNN  — 

Two Australian states are bracing for a day of “catastrophic” risk as firefighters battle over 100 deadly active bushfires that have produced clouds of smoke seen as far away as New Zealand.

Thousands of people are in the paths of the blazes in the states of Queensland and New South Wales, which have both declared a state of emergency.

On Tuesday morning, state authorities warned that although the situation was “calm” at the moment, eastern Australia was still facing a “very long and very dangerous day ahead.”

Strong winds, high temperatures, and low humidity could provide perfect conditions for dozens of fires to spread further today.

The “catastrophic” warning is the worst threat level ever issued for New South Wales’ capital, Sydney, under the current system, which was introduced in 2009.

The city is home to around 4.6 million people, but the greatest fire risk lies in rural areas outside the city center. They include the greater Hunter area, Illawarra, and Shoalhaven, which are also facing “catastrophic” fire threats.

“The only safe place to be is somewhere else,” Stuart Ellis, chief executive of the Australasian Fire and Emergency Service Authorities Council, told national broadcaster, ABC.