If the smoke haze wasn't enough of a stark reminder of the bushfire devastation across NSW, ash and blackened leaves washed up on Sydney beaches over the weekend.

At 9pm on Sunday, 91 fires were burning across the state.

The NSW Rural Fire Service said 48 were uncontained and six were at watch and act level.

Among them was the enormous Gospers Mountain blaze in the Wollemi National Park area which is more than 307,000 hectares in size. Multiple fires have joined to create what is now known as a "megafire".

RFS deputy commissioner Rob Rogers said firefighters were concerned about it pushing into Gosford, noting Sunday's mission was to protect properties and people as much as possible.

The RFS said "more favourable conditions" allowed for critical back-burning operations ahead of another challenging week.

"We are expecting a return to another hot day, particularly Tuesday," NSW RFS commissioner Shane Fitzsimmons said on Sunday.

"We're expecting to see temperatures climb into the high 30s or early 40s right across parts of NSW, so a lot of work ahead over the coming days, particularly in anticipation of what's expected."

Smoke haze will descend on Sydney again late on Monday - mainly in the west but extending to the east in the evening - and remain on Tuesday, according to the Bureau of Meteorology

The BOM has forecast 2019 to rank among Australia's warmest and driest years on record.

In Queensland, a series of welcome storm cells swept across the state on Sunday evening.

BOM meteorologist Lauren Pattie told the Courier Mail they had dumped rain on some areas impacted by bushfires, and there had been a storm over the Mount Stanley bushfire that's been burning for days near Kingaroy.

The fire danger rating in Queensland's Northern Goldfields and Upper Flinders regions on Monday is severe.

In Victoria, a total fire ban has been issued for swathes of the state ahead of forecast scorching temperatures and strong winds.

The Mallee, Wimmera and Northern County regions will be under a total fire ban on Monday, with very high to extreme fire danger expected.

Gusts of up to 70km/h are also forecast for the northwest, with an expected high of 43C in Mildura and 42C in Swan Hill.

Melbourne won't be as windy but the city is still set to hit 39C.

Meanwhile, an emergency-level bushfire at Newland on Kangaroo Island in South Australia was downgraded over the weekend but still considered watch and act level on Sunday night.

The southern state's Mid North, Flinders and Riverland regions will remain under total fire bans on Monday, each categorised as having a severe fire danger rating.

Severe and very high fire danger ratings have also been issued for parts of Western Australia.

- with AAP