Third warmest year on record for Australia

Australia has had its third hottest year on record.

Queensland and NSW experienced their warmest years on record in 2017 as the trend of warmer than average temperatures across Australia continued, the Bureau of Meteorology says.

"Despite the lack of an El Nino - which is normally associated with our hottest years - 2017 was still characterised by very warm temperatures," its head of climate monitoring Dr Karl Braganza said.

The national mean temperature of 22.76C - or 0.95C above the long-term average - was the third highest since records began in 1910.

Both day and night-time temperatures were warmer than average, with the maximum for the year the second highest on record.

Prolonged high sea surface temperatures led to the first instance of back-to-back years of mass coral bleaching events on the Great Barrier Reef.

Dr Braganza said dry and cloud-free conditions across much of southeast Australia during June and July led to warm, sunny days and very chilly nights.

After a wet start to 2017, the middle of the year was notably dry.

June was the second-driest on record nationally and September the driest for the Murray-Darling Basin, Dr Braganza noted.

He said there has been a gradual decline of about 10-20 per cent in rainfall during the cooler months of the year.

Seven of Australia's 10 warmest years have occurred since 2015.

Dr Braganza said 2017 is likely to have been among the three warmest years on record globally.

"Australia has been looking at an increased frequency of heatwaves and other extremes that have been positively associated with climate change," he said.