Southern Australia’s worsening droughts and catastrophic bushfires are being driven by dramatic shifts in the upper atmosphere, according to new research published by academics from Australian universities through The Conversation.
The study finds that powerful jet streams high above the continent have moved significantly southward in the past decade, dragging vital winter rain systems away from southern coastlines and leaving major population centres increasingly dry and vulnerable.
Upper Atmosphere Changes Reshape Australia’s Climate
Researchers identified a marked shift in fast-flowing jet stream air currents located about 8 to 10 kilometres above Earth’s surface. These currents, which typically steer rain-bearing cold fronts across southern Australia, have migrated roughly 10 degrees of latitude nearly 1,000 kilometres toward the South Pole since 2015.
As a result, traditional winter rainfall systems are now tracking south of the continent, bypassing key agricultural and urban regions. Southern Australia stretching 4,000 kilometres from Perth to east of Melbourne and home to around 10 million people has experienced at least 25% less annual rainfall in recent years.
The findings link these atmospheric changes directly to the 2017–19 “Tinderbox” drought and the ongoing drought that began in 2023 and continues into early 2026. Six of the past ten years have recorded dry conditions across much of the region.
In stark contrast, eastern Australia, including Sydney and Brisbane, has experienced periods of extreme rainfall and flash flooding, highlighting a growing climatic divide across the continent.
Major cities are already feeling the strain. Melbourne, Adelaide and Perth have reported declining reservoir levels as reduced winter rainfall limits water inflows. Melbourne’s water storage has dropped to around 70% capacity its lowest level since the Tinderbox drought prompting the reactivation of its desalination plant in 2025.
Adelaide has quadrupled desalination output to meet demand after three exceptionally dry years, while Perth, which has faced a long-term rainfall decline since the 1970s, is building a third desalination facility.
Researchers attribute the jet stream relocation to ongoing global warming driven by greenhouse gas emissions. As ocean and atmospheric temperatures continue to rise, the jet streams are expected to shift further poleward, potentially intensifying drought patterns in southern Australia.
The consequences extend beyond water shortages. Reduced winter rainfall leaves vegetation dry and highly flammable, increasing the likelihood of severe bushfire seasons. Over the summer of 2025–26, extreme heat and dry westerly winds contributed to catastrophic bushfires across Victoria, burning more than 430,000 hectares.
Experts warn that a possible El Niño later in 2026 could further worsen drought conditions, compounding risks for water security and fire management.
The researchers describe the findings as a wake-up call for governments, primary producers and urban planners. With atmospheric circulation patterns shifting under climate change, southern Australia may need to prepare for a future defined by hotter, drier winters and more frequent fire emergencies.