Heatwaves and bushfires are predicted in southern Australia while cyclones may ease up in the north by the end of the year thanks to a 70 per cent chance of El Nino weather conditions.
This tripled the likelihood of an El Nino system forming to bring drier than normal conditions by the end of 2018, the Bureau of Meteorology warns.
"Between the (above average) temperature and the lack of rainfall, this is not good news," bureau climatologist Robyn Duell told AAP.
"This outlook on the back of such little rainfall and dry conditions makes it such a worry for people."
Australia endured its driest September since rainfall records began in 1900, Ms Duell said.
The eastern tropical Indian Ocean is cooler than normal while the western part of the ocean is warmer than usual, which is common with El Nino, she said.
The warning comes as NSW and Queensland is bone-dry with drought conditions worsening into parts of Victoria where farmers are struggling to save their crops.
Australian Associated Press