Increasingly ferocious bushfire seasons that raze homes, claim lives and decimate wildlife from the Australian landscape are becoming the new normal.

A trend of more severe and frequent fire seasons that run for longer has well and truly set in, the Bureau of Meteorology says.

Last year was Australia's hottest and driest on record, laid bare in the BoM's annual climate statement for 2019.

"Australia's climate is warming," Dr Karl Braganza, head of climate monitoring at the BoM said.

"We're getting certain kinds of weather, particularly heatwaves and fire weather, they're becoming more frequent and more extreme.

"That information really is going through to those responsible for managing climate risk."

Twenty-five people have been killed in the current bushfire season, more than 2000 homes flattened and a total land mass almost as big as England has become a blackened wasteland.

There is an expectation that fires which have burned for months will continue to savage communities and further tear through the landscape for months more.

Last year being the hottest and driest on record was a key factor influencing fire conditions.

The BoM's head of long-range forecasting Andrew Watkins says rainfall is forecast to ease back towards a more neutral pattern in the coming months.

But we are not likely to see the widespread, above-average rainfall needed to put fires out quickly.

"It is going to be a campaign in terms of the fires, we're not looking at a short and sharp end to the event. It does look like something we'll have to persist with for some time," he told reporters on Thursday.

Much of the country is affected by drought, while the national average rainfall total dipped to 277mm, the lowest since consistent national records began in 1900.

The previous driest year was 1902, when the national average was 314mm.

Rainfall deficiencies have exacerbated the drought and created prime conditions for a prolonged inferno.

"Australian temperatures have increased by 1.4 degrees since 1910 and most of that warming has occurred since the mid-20th century, so that's a shift in the entire frequency of weather," Dr Braganza told reporters.

It means years like 2019 are more likely to occur again and again.

Bushfire seasons in Queensland and northern NSW tend to start earlier before being killed off by monsoonal weather.

That wasn't the case in 2019, when more severe weather typically experienced towards the end of the season came earlier.

Dr Braganza said the contribution of climate change to a single weather event was difficult to determine and required particular modelling.

However, that doesn't mean it isn't influencing what Australia is seeing.

"(But) we can be clear on the things we do know," he said.

"We know that there's a trend in both the severity of fire weather, the frequency of it, and an extension of the season."