Summer temperatures are forecast to soar above their usual average, while the chances of more bushfires and an El Nino developing are on the rise.
The Bureau of Meteorology's latest outlook for summer warns that most of Australia has an 80 per cent chance of higher-than-normal temperatures between December and February.
Meanwhile, the chance of an El Nino forming in 2018 and bringing even more drier and warmer conditions to eastern Australia is now at 70 per cent, roughly triple the normal risk.
"We've already seen extremely hot temperatures through parts of north and central Queensland in recent days and this should act as an important reminder of the kinds of conditions we can get during an Australian summer," the bureau's manager of long-range forecasting Dr Andrew Watkins said on Thursday.
The forecast of a long, hot summer has increased the chances of Australia recording one of its warmest years on record and sparked fresh warnings about the heightened bushfire risk across southern Australia.
While parts of the drought-stricken eastern states have enjoyed some recent rain and there's been huge downpours along the NSW coast during this week's storms, experts are warning it won't be long before the hot summer temperatures dry out ground vegetation.
"Above-normal fire potential remains across large parts of southern Australia," the Bushfire and Natural Hazards Cooperative Research Centre said in its seasonal bushfire outlook, also released on Thursday.
As part of its summer outlook, the Bureau of Meteorology forecast a drier-than-average summer for large parts of Queensland, Western Australia and the Northern Territory.
"Having said that, locally heavy rainfall events similar to what we have seen in NSW in the last two days are always a possibility during summer, no matter what the outlook is showing," Dr Watkins said.
NSW has recorded its eighth driest and fourth hottest April-November on record, with Queensland and Victoria having experienced similar conditions.
That dry, hot weather that stretched from autumn into spring is now driving expectations of an above-normal fire risk this summer for large parts of Queensland, NSW, the ACT, Victoria, Tasmania, South Australia and Western Australia.
The Bushfire and Natural Hazards CRC said several months of above-average rainfall is needed to improve the general dryness across the landscape.
"The dry landscape means that any warm windy conditions are likely to see elevated fire risk," it said.
"Recent rainfall has not been significant enough to drastically change the vegetation (fuel) loads, with many southern and eastern areas already cured or carrying little grass growth."
