Australian summers are getting longer and winters shorter, analysis of weather data shows.
The warning comes as a new report by independent researchers shows Australia's temperatures are rising faster than the global average and could warm by up to four degrees by the end of the century.
Speaking in Canberra today, Bureau of Meteorology CEO Andrew Johnson said the risk of severe fire danger is only set to continue.
He said Australia is on track for a temperature rise of four degrees by the end of the century, outpacing the predicted global temperature increase of 3.4 degrees.
"We know that the drying trend will continue, particularly between southeast Australia and southwest Australia, we know the warming trend will continue, we know the number of hot days will continue, as I answered previously we know that the risk of severe fire weather will continue," he said.
Summers in Port Macquarie on the NSW mid-north coast are seven weeks longer than they were in the 1950s and 60s, according to new research from the Australia Institute.
The Institute's climate-energy program director Richard Merzian said official weather records show global warming has already caused major changes to our seasons.
"If you look at just the last five years rather than the last 20, given that things have really been heating up, you're now seeing summers that are twice as long as winters," he said.
The study found that across Australia, a regular three-month summer now spans from November to mid-March.
Sydney experiences an extra 28 days of summer temperatures. Adelaide, an additional 36 days. And Melbourne, 38.
NSW Rural Fire Service Deputy Commissioner Rob Rogers said longer summers mean firefighters have less time to prepare for future bushfires.
'What we've found over the last couple of years is either it's been too dry for hazard reduction burns or sometimes too wet so we have a limited window of opportunity and we have to look at making sure we can take advantage of that whenever we can but obviously that is problematic and has been problematic for us over the past few years," he said.
Former fire chiefs from across the nation, including former Victorian Country Fire Authority CEO Neil Bibby and former New South Wales Fire Commissioner Greg Mullins, have banded together to call for stronger government action on climate change.
"The fires are a symptom of a disease and the disease is climate change, there's no use attacking the symptoms if you don't attack the disease itself so we're asking that Australia lead the way in looking at climate change and how to bring the temperatures down," he said.
The Federal Government has set a target to reduce its emissions by 26 to 28 per cent from 2005 levels by 2030.