SYDNEY - Australia must brace for longer and more dangerous fire seasons and marine heatwaves in the years ahead, while swift changes in weather patterns might result in more hot days and fewer cool days, a government report said on Thursday.

The oceans around Australia are continuing to warm, with increases in carbon dioxide in the atmosphere leading to more acidic oceans, particularly in the country's south, said the Bureau of Meteorology and national science agency CSIRO in their biennial joint climate report.

"Rising sea levels around Australia are increasing the risk of inundation and damage to coastal infrastructure and communities," CSIRO Research Manager Jaci Brown said in a statement accompanying the report.

Australia, a major crops producer, has experienced over the last decade extreme weather events such as frequent flooding, droughts, marine heatwaves and devastating fires that some experts attribute to climate change.

Heavy rainfall events are becoming more intense, with an increase of around 10% or more in some regions, though the average duration of drought is expected to rise in the country's south and east in the decades ahead, the report said.

Australia is continuing to warm, with eight of the nine warmest years on record occurring since 2013, said Karl Braganza, climate services manager at the weather bureau.

"This warming has led to an increase in extreme fire weather, and longer fire seasons across large parts of the country," Braganza said.

A shift toward drier conditions between April and October across the country's southwest and southeast, and lower rainfall in the southwest could become a permanent feature of Australia's climate, the report said.

Coastal floods that occur occasionally will become chronic later this century, while the warming and acidification of oceans will cause more severe bleaching events in coral reefs, including the Great Barrier Reef.

Coral bleaching happens when the water gets too warm, causing corals to expel the colourful algae living in their tissues and turn white.