Australia's Year of Extremes: The 2026 Weather Crisis

From record-breaking heat to catastrophic floods, Australia endured one of its most volatile weather years on record.

The year 2026 saw Australia lurch between climatic extremes—prolonged heatwaves gave way to devastating floods, while multiple tropical cyclones battered the north. The nation's weather was driven by a volatile mix of El Niño and La Niña transitions, the Southern Annular Mode (SAM), and the relentless pressure of global warming.

Prolonged Warmth and Early Season Heat

The year opened with unseasonably warm weather across much of the continent. In late April and early May, a large high-pressure system blocked cold fronts from the Southern Ocean, trapping heat across the south.

May Warmth

On May 1, 2026, Melbourne, Adelaide, and Hobart experienced maximum temperatures approximately 10 degrees Celsius above their May averages. Sydney recorded its second-warmest May on record, while other capitals also reported top-five warmest Mays.

Numerous stations across New South Wales, Victoria, South Australia, and Tasmania recorded their warmest May day on record on May 1.

The Bureau of Meteorology (BOM) attributed this warmth to a combination of climate change, abundant cloud cover trapping heat overnight, and a lack of strong cold fronts.

Winter Outlook

The BOM forecast one of the warmest winters on record for southern states, with daytime temperatures expected to be 1-2°C above recent decades.

Record-Breaking Rainfall and Widespread Flooding

Following the early heat, a dramatic shift in weather patterns brought prolonged and intense rainfall to much of the country, triggering major flooding across central, eastern, and northern Australia.

May Rainfall

May 2026 delivered record-breaking rainfall, particularly in the southeast, driven by a series of low-pressure systems and a northwest cloudband.

• Gold Coast: 190mm in 24 hours (heaviest May day since 2003)
• Dubbo: 134mm (wettest May since 1983)
• Renmark, SA: 123mm (wettest May on record)

A slow-moving upper-level trough interacting with tropical moisture from a northwest cloudband was the primary cause.

Central and Eastern Australia Floods (Late Summer/Autumn)

From February into March, a slow-moving tropical low over central Australia caused extreme rainfall affecting South Australia, Queensland, New South Wales, Victoria, and the Northern Territory.

Many arid areas received a year's worth of rain in a matter of days or weeks.

• Oodnadatta, SA, recorded 136mm.
• Mount Isa, Qld, recorded 318.6mm—its wettest February on record.
• Uluru received over 100mm in under 30 hours in March.

Widespread flash and riverine flooding occurred. The East West rail line near Port Augusta was closed due to 100-meter track washaways. Sydney experienced flash flooding with over 3,000 power outages and 40 flood rescues. At one point, the Bureau of Meteorology issued flood watches for nearly half the country.

Northern Territory Flooding (March-May)

Heavy rainfall from tropical lows caused major, record-breaking flooding in the Top End, notably in Katherine and along the Daly River.

The Katherine River peaked at 19.2 meters on March 7—the highest level since 1998. The town was evacuated, the hospital closed, and a field hospital established. Over 700 residents sheltered in emergency accommodation.

The Nauiyu community was evacuated twice in two months as the Daly River reached a record level of 16.38 meters in March. All buildings in the town were reported underwater.

Nearly 90% of roads in the central and Barkly regions were damaged.

The flooding isolated numerous remote communities, cut major roads like the Stuart Highway, and prompted warnings about crocodiles in floodwaters.

Northern Queensland Floods

Northern Queensland experienced a series of flood events from December 2025 through the first half of 2026.

• Significant Livestock Losses: Flooding resulted in the loss of over 16,000 head of livestock in north-western Queensland, a figure that later grew to an estimated 24,200.
• Tropical Lows and Cyclones: The region was repeatedly impacted. Ex-Tropical Cyclone Koji made landfall near Ayr in late January, while a tropical low (29U) caused severe flooding in Far North Queensland in March.
• Saturated Catchments: The region's waterlogged catchments remained vulnerable to flash and riverine flooding from any subsequent rainfall.

Tropical Cyclone Activity

The 2025-26 wet season was highly active, with multiple tropical cyclones and lows forming in Australian waters.

Cyclone Koji

Developed in the Coral Sea in late January, making landfall as a Category 1 system between Ayr and Bowen, Queensland. It was later downgraded to a tropical low.

Cyclone Narelle

Developed into a severe tropical cyclone in the Coral Sea in March. It was forecast to potentially make landfall in Far North Queensland as a Category 4 system but tracked west, passing north of Katherine, NT, as a tropical low. It was the seventh "high-risk weather event" for the Northern Territory in five months.

Other Lows

Numerous tropical lows—including 12U, 29U, 31U, 34U, and 37U—formed and impacted various parts of the north, bringing heavy rain and flood risks. A tropical low near Darwin caused an unprecedented shutdown of the Darwin River Dam's pump station due to flooding in March.

Kati Thanda-Lake Eyre Inflow

The exceptional rainfall in central Australia triggered a historic event.

The lake was on track to reach full capacity for the first time in 50 years.

Satellite imagery showed floodwaters from Queensland's Channel Country rivers flowing into Kati Thanda-Lake Eyre. The inflow sparked a major ecological event, with greening of the landscape and an expected influx of birdlife.

Agricultural and Economic Impacts

The extreme weather had a profoundly mixed impact on agriculture and infrastructure.

• Beneficial Rain: The widespread rain provided drought relief and replenished water supplies in many farming regions.
• Crop and Livestock Losses: However, the timing and volume of rain caused problems. Grape growers in the Murray Valley reported crop losses from berries splitting and bunch rot. The loss of an estimated 24,200 head of livestock in north-western Queensland was a severe blow to the cattle industry. Flooding also damaged extensive fencing and private roads.
• Infrastructure Damage: Damage to the East West rail line and closure of the Stuart Highway disrupted freight and transport routes. Roads in central and northern Australia were extensively damaged.

Climatic Context

El Niño and La Niña

The BOM declared an El Niño in June 2026, which is typically associated with drier conditions in eastern and southern Australia. However, the earlier rainfall events were attributed to other factors, including a strongly positive Southern Annular Mode (SAM), which drew moisture-laden air from the east. The El Niño declaration was later followed by forecasts for a drier-than-normal winter and spring for much of Australia's south and east.

Global Warming

The BOM has stated that global heating is increasing Australia's vulnerability to extreme weather, including intense rainfall.

The atmosphere can hold approximately 7% more moisture for each 1°C of warming, making extreme rainfall events more likely as the planet continues to heat.