SYDNEY (AFP, REUTERS) - Australia suffered its hottest summer on record from December through February, and forecasts show the southern autumn will continue to be drier and warmer than average, the government said on Thursday (Feb 28).

"After a record hot December and January, it won't come as a surprise that this summer will be our warmest on record," said Mr Andrew Watkins, manager of long-range forecasting at the Bureau of Meteorology, the federal government's weather agency.

Although the final figures won't be available until Friday (March 1), the bureau said it was already clear the average maximum and mean temperature for the three months of summer would, for the first time, be more than 2 deg C higher than long-term averages.

Rainfall was also below normal, and the bureau said it saw no let-up in a severe drought that has gripped vast areas of the country's agricultural heartland in the east and south-east for many months.

"Unfortunately, the outlook isn't giving a strong indication that we'll see a return to average or above average rainfall in many areas over the autumn period," Mr Watkins said.

The bureau reported earlier that January had been the hottest month ever recorded in Australia, with mean temperature across the continent exceeding 30 deg C for the first time.

Mr Watkins said weather patterns over the Indian and Pacific oceans contributed to the higher temperatures and lower rainfall, but that long-term climate change trends were also involved.

The authorities said the January heatwave contributed to the deaths of more than a million fish in the Murray-Darling river system, the country's largest and which runs through five states in the east of the country.

Meanwhile, bushfires - which are frequent summer occurrences in Australia's arid south-east - spread far into the tropical north-east of the country in January.

Separately, the dry conditions are also set to curb wheat crop yields for a third straight year in Australia, the world's No.4 exporter of the grain, a private US-based weather forecaster said on Wednesday.

Successive years of drought that have wilted crops and left some farmers struggling to stay in business. Declines in Australian wheat production in the 2019/20 crop year could buoy global prices that on Wednesday struck their lowest in 10 months.

"Over the next three to six months, we expect drier-than-normal weather in parts of Queensland and New South Wales," said Mr Kyle Tapley, senior agricultural meteorologist at Radiant Solutions, formerly MDA Earthsat. "This is an area of concern, as it is already dry," he told Reuters on the sidelines of a grains conference in Singapore.

Australia's wheat production fell to an 11-year low during the 2018/19 season, according to the country's chief commodity forecaster. Output totalled 17.3 million tonnes, down from 21.24 million tonnes a year earlier, the Australian Bureau of Agricultural and Resource Economics and Sciences said in its final tally for the crop. Australian farmers will begin sowing wheat for the 2019/20 season in April.|