South Australia suffered its driest year on record during 2019, the Bureau of Meteorology (BOM) says, with rainfall down 65 per cent as mean temperatures rose 1.45 degrees Celsius higher than the long-term average.

Key points: Every month except August endured above-average temperatures in SA, with a record dry spell between January and April

Every month except August endured above-average temperatures in SA, with a record dry spell between January and April Average rainfall in the state was down 65 per cent to become its driest year on record

Average rainfall in the state was down 65 per cent to become its driest year on record Adelaide endured its hottest day on record on January 24 when it reached 46.6C, beating the mark set 80 years earlier

Releasing the 2019 Annual Climate Statement today, BOM head of climate monitoring Karl Braganza said every month apart from August endured above-average temperatures in SA, while there was a record dry spell between January and April.

"It was very dry, the driest year on record, with average rainfalls of about 80 millimetres [down 65 per cent from the long-term average]," he said.

"We've got several locations throughout the interior where we got less than 30mm rainfall for the year."

The bureau said 2019 was South Australia's second hottest year on record.

Adelaide endured its hottest day on record on January 24 when it reached 46.6C, beating the 46.1C recorded in 1939.

Lake Eyre fills despite big dry

Australia's annual mean temperature was 1.52C above average and its overall rainfall down 40 per cent.

This is despite February's Townsville floods, which exceeded local rainfall records.

Floodwaters near Birdsville make their way towards Lake Eyre during February. ( Supplied: C. Ellis )

"What we did see is the floodwaters eventually making their way to Lake Eyre or Kati Thanda," Dr Braganza said.

"That's the most significant filling of the lake since 2010-11 in the midst of all the rainfall deficiencies around that location."

Australian maximums up 2C

Dr Braganza said daytime temperatures across the country in 2019 were above their average maximums by a whopping 2.09C for the first time in recorded history.

"We also saw the six hottest days on record, peaking at 41.9C [on average across the country]," he said.

"We saw 11 such days where the national daily temperature [on average] went over 40C this summer, and that is really quite stark.

A map revealing above average temperatures Australia-wide during 2019. ( Supplied: Bureau of Meteorology )

"There were two such days in 1972-73, two in 2013, seven last summer and 11 this summer. So that's really indicative of how widespread that heat is."

Dr Braganza said there were multiple factors behind the hot and dry weather including a strong Indian Ocean Dipole (IOD) event, or sustained change in the difference between sea surface temperatures in the western and eastern Indian Ocean.

There was also a rare and sudden stratospheric warming event above the South Pole which pushed Australian weather systems northward and "compounded the warmer and drier than average conditions over southern Queensland and New South Wales during spring, amplifying the fire weather".

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 27 seconds 27 s This is how sudden stratospheric warming occurs ( Supplied: National Institute of Water and Atmospheric Research (NIWA) )

Global warm a 'key factor'

Dr Braganza added that global warming had been a "key factor" because Australia had warmed by more than one degree since 1910 — mostly since the mid-20th century.

"You can consider that most of the weather is occurring in a climate system that is about one degree warmer," he said.

"So that will tend to push things towards record territory.

"We've got very well-defined and clear trends underlying the changes we've seen over the past couple of decades."

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Dr Braganza said a delayed monsoon season, which typically helped to cool the country's interior, had also contributed to hot weather over summer.

"There's nothing really indicating that things will cool down too much over the next few months, although we are starting to see some signs that the monsoon season is starting to get active," he said.

BOM's climate outlook overview, released last week, found that SA and Western Australia could receive average to wetter-than-average conditions in January, despite eastern Australia remaining drier than average.

That potential for wetter conditions was expected to weaken through February and there was no strong tendency towards wetter or drier-than-average conditions up to April.

BOM said days and nights were likely to remain warmer than average through to April.