The New South Wales Rural Fire Service says there’s a “very high to severe fire danger forecast” across the Australian state today as hot, gusty winds exacerbate dry conditions.

The fire service said 45 bush and grass fires are burning across the state – all at advice level, and total fire bans are in place across nine regions.

The Bureau of Meteorology has forecast a high of 40 degrees Celsius for Sunday in Sydney’s CBD, with winds from the north and north-west reaching 45 kilometres an hour before shifting south to south-easterly in the late afternoon.

Fire Service commissioner Rob Rogers warned the rapid spread of grass fires could catch people unawares.

“If those fires do start, particularly in those grassland areas, they’ll move really, really quickly,” he said.

“People don’t want to get caught in front of a grassfire.

“They’re different to a bushfire. They burn really hot really quick.”

Meteorologist Helen Kirkup said a cool southerly change expected later in the afternoon would see temperatures drop.

“Along the coast we’ll see this change to come round from Victoria in the late morning, and we’re expecting the timing of this change to be through Sydney, somewhere between maybe 3pm and 5pm during today, and then up to the Hunter by the evening,” she said.

Record-breaking heat

Kirkup said hot weather records have been broken this weekend.

“There were a few places that recorded record maximum temperatures, as in the hottest November night-time for a while.

It's been a hot and sweaty night across many parts of NSW, with grass fires and record highs in some areas.

It’s been a hot and sweaty night across many parts of NSW, with grass fires and record highs in some areas. Photo: Supplied/ New South Wales Rural Fire Service

“Sydney Observatory Hill only went down to 25.3 degrees around 1:30am, and that was the coolest it made it to all night, and that’s because of a fairly strong westerly wind that’s been dragging warm, hot air across the region for parts of yesterday, right overnight and that will continue today.”

The previous highest November night temperature at Observatory Hill was 24.8 degrees in 1967.

“Another place, Cobar, only went down to 28.9 which is a November record for them and that’s a station that has 59 years of data so quite a long record there,” Kirkup said.

“The other places that appear to have broken annual records, and this needs to be verified by out climate team during the week, but Bankstown Airport which has a 53-year-old record only went down to 27.1 which is an annual record for them, as well as the Camden Airport.”

Hundreds of people flocked to Manly Beach before 8 am Sunday morning, with Sydney’s temperature already soaring over 30C.

With a high overnight minimum, there was no reprieve from the heatwave on Saturday night.

A strong north-westerly is keeping much of the coastal breeze at bay, meaning even coastal areas in Sydney are tipped to hit the 40C mark.

-ABC