Australia’s southeast is bracing for another day of spring heatwave conditions as firefighters battle to bring several blazes under control in unseasonably hot weather.

A severe heatwave warning was in place for parts of the NSW south coast on Monday and the sweltering conditions were expected to continue until Wednesday.

Temperatures were expected to reach a maximum of 31C in the Sydney city centre on Monday before rising to 34C later in the week, while the mercury was tipped to rise to as high as 36C in the western suburbs.

Similar peaks were likely on much of the NSW coast until Wednesday, while temperatures were also forecast to soar across much of inland Australia, the Bureau of Meteorology said.

Beginning from Wednesday, the heat was expected to shift north into parts of Queensland, the Northern Territory and Western Australia, driving highs of up to 40C.

NSW Rural Fire Service volunteers worked overnight into Monday to bring a bushfire near Cessnock in the Hunter region under control after it threatened properties at Neath.

RFS commissioner Rob Rogers said firefighters were still working to contain fires on the state’s north coast as temperatures increased and conditions worsened.

“The difficulty is that there is quite a lot of grass fuel that’s carrying the fires and making them burn quicker than you would normally expect and obviously (combined with) that very unseasonably warm weather,” he told ABC Radio.

But Mr Rogers said firefighting efforts were boosted by the addition of a Chinook helicopter, delivered in July, which would not have been available this early in the season if authorities had to rely on aircraft contracted from overseas.

In Queensland, firefighters have brought blazes at Emerald, in the central highlands, and Beerwah, on the Sunshine Coast, under control, although they are bracing for hotter temperatures later in the week.

– AAP