Australia’s summer swings from 50°C heat to flooding rains, testing communities and farms

On a blistering Saturday in late January, the temperature at Port Augusta in South Australia hit 50 degrees Celsius, hot enough to warp bitumen and keep people indoors behind drawn blinds. Fire authorities warned that “everything is ready to burn.”

Less than five weeks later, emergency crews in the same state were hauling sandbags and closing outback roads as a slow-moving tropical low delivered a year’s worth of rain in days across normally parched country stretching into Victoria and New South Wales.

Australia’s 2025–26 summer was defined by that kind of whiplash: a season that was simultaneously one of the hottest and one of the wettest on record, with swings from extreme heat and fire danger to inland flooding that cut off remote towns and swamped vineyards at harvest.

A summer of extremes

The Bureau of Meteorology said the summer, spanning December to February, was the nation’s eighth-warmest since records began in 1910 and the wettest since 2016–17. The national mean temperature was 1.1 degrees above the 1961–1990 average. Area-average rainfall came in 32% above the long-term norm.

“It was a very extreme season,” said Dean Narramore, a senior meteorologist at the bureau. “We’ve had severe heatwaves, we’ve seen temperatures hit 50 degrees, and then we’ve had very impressive and in some areas record-breaking rainfall just a few weeks later. That’s really quite remarkable.”

Nine of Australia’s 10 hottest summers have occurred since 2012–13. Only one summer from the 20th century, 1997–98, ranks hotter than this year.

Heat and fire danger

The fiercest heat arrived in late January. Between Jan. 26 and 31, 62 weather stations across the country recorded their highest daily maximum on record. The hottest readings of the season were 50.0 degrees at Andamooka in outback South Australia on Jan. 29 and at Port Augusta Airport on Jan. 30, according to bureau data.

Much of central and southern Australia endured several days of intense heat, with overnight minimums staying in the high 20s or even low 30s in parts of Western Australia and the Northern Territory. Health authorities issued warnings about dehydration and heat stress, particularly for older people, young children and outdoor workers.

The severe heat coincided with heightened bushfire danger, especially in Western Australia, Tasmania and Victoria, where dry lightning and high fuel loads helped drive multiple significant blazes. The current 2025–26 bushfire season has already destroyed hundreds of homes and claimed several lives.

“Heatwaves are Australia’s deadliest natural hazard, and they’re becoming more intense, longer and more frequent as the climate warms,” said Andrew King, a climate scientist at the University of Melbourne. “What we saw this summer — those very extreme temperatures over a wide area — is consistent with that trend.”

The pattern flips: monsoon low brings inland flooding

While January was drier than average nationally, the pattern flipped in February.

A monsoon low developed near the Northern Territory–Queensland border and then drifted only a few hundred kilometers over the course of a week. Its sluggish pace, combined with deep tropical moisture, allowed storm bands to repeatedly cross central and southern inland areas.

By the final week of February, parts of central and northern South Australia, north-west Victoria and western New South Wales were under intense rain and flash flooding.

In South Australia, the bureau said February rainfall was 356% above the long-term average, making it the state’s second-wettest February on record. Large areas of the northeast, around the Lake Eyre basin, recorded their highest February totals.

At Kalamurina, northeast of Kati Thanda–Lake Eyre, gauges collected about 240 millimeters of rain by Feb. 25, more than the region’s average annual total and a record for the station. At Arkaroola in the northern Flinders Ranges, 228 millimeters fell over the month, the wettest in 37 years of records.

Marree, on the edge of the desert in outback South Australia, logged 136 millimeters in a single week — compared with just 37 millimeters during all of 2025.

Across the border in Victoria, the usually dry Mallee region also broke records. Mildura received close to 150 millimeters in a week, nearly matching its total rainfall for all of the previous year. The town of Ouyen recorded 92.6 millimeters on Feb. 25, its wettest day on record.

Narramore described the event as “very impressive” and said it produced “weather whiplash” for communities that had just endured a severe heatwave.

Emergency response and isolation in the outback

The downpours pushed water rapidly through inland river systems. In western Queensland, the Diamantina and Georgina rivers rose, isolating the outback town of Birdsville by road. Highways to Bedourie and Windorah were cut, and supplies were flown in for several days. The Bureau of Meteorology warned that, even as rain eased, floodwaters would keep moving downstream toward Lake Eyre for weeks.

State emergency services dealt with hundreds of calls across the affected regions.

In Victoria, the State Emergency Service said it received 392 requests for assistance between early Sunday and mid-morning Monday during the peak of the event, 143 of them in Mildura alone. Most were for flooding, building damage and fallen trees.

In New South Wales, the State Emergency Service issued a severe weather warning on Feb. 24 for western districts including Broken Hill, Menindee and Wentworth. Forecasters predicted 50 to 90 millimeters of rain in 24 hours, with isolated totals up to 130 millimeters and a high risk of flash flooding.

In South Australia, the SES issued broad flood watches from Feb. 23 across outback regions, cautioning that fast-rising waters could make roads impassable and isolate remote communities. Authorities repeatedly urged motorists not to attempt to drive through floodwaters.

Harvest hit as vineyards see “months’ worth of rain”

In some places, the timing of the rain compounded existing pressures rather than bringing relief.

Along the Murray, Darling and Swan Hill regions, many winegrape growers were harvesting — or about to start — when 100 to 180 millimeters fell in about five days.

“Most of our growers got months’ worth of rain right when they didn’t need it,” said Paul Derrico, chief executive of Murray Valley Winegrowers, which represents about 260 growers in north-west Victoria and south-west New South Wales. “You get berry swell, you get splitting, you get bunch rot. And if the machinery can’t get in because it’s too wet, you can’t even get the fruit off.”

Derrico said many growers were already under financial strain from low grape prices and oversupply. “There’s a real risk some will end up with little or no income from this harvest after a full year of costs,” he said.

The same rain has left a bank of soil moisture that agronomists say could prove valuable for winter crops such as wheat and barley, particularly in parts of South Australia and Victoria. But for perennial crops like vines and for summer harvests, it has been damaging.

Ecological consequences from Lake Eyre to flying foxes

The inland deluge has also reshaped the landscape in ways that go beyond human infrastructure.

Hydrologists say the Lake Eyre basin had its third-wettest February on record and that Kati Thanda–Lake Eyre is likely to fill for a second consecutive year. In past decades, major fillings of the vast salt lake have been rare events associated with large inflows from Queensland and the Northern Territory.

“Sequential wet years often precede the really big lake-filling events,” said river ecologist Fran Sheldon, who has studied the system for decades. “When those floodwaters spread out, you see an explosion of life — fish breeding, waterbirds arriving in huge numbers, and floodplain plants responding.”

The ecological boom stands in stark contrast to scenes just weeks earlier, when a separate heatwave killed large numbers of flying foxes in eastern states. Wildlife groups reported more than 80% of a colony dead in one roost as temperatures soared.

Climate change and “weather whiplash”

Scientists say Australia’s environment is adapted to swings between drought and flood but warn that climate change is amplifying both ends of the spectrum.

“As the atmosphere warms, it can hold more moisture, which means when the right weather systems line up, we can get more intense downpours,” King said. “At the same time, background warming is driving more extreme heat. So you end up with this increased risk of very hot, dry periods followed by very heavy rainfall, sometimes in the same places and the same season.”

The pattern is straining systems built for a more stable climate.

Volunteer-based emergency services are confronting back-to-back fire, heat and flood campaigns. Rural roads, bridges and drainage in low-lying inland areas are being tested by rainfall intensities that were once considered rare. In cities, flash flooding from short, intense bursts has closed major arteries and required dozens of swift-water rescues.

For many communities, the summer has been a reminder that risk no longer comes in single hazards.

In one season, Australians have faced record-challenging heat, destructive fires, inland rain that has broken long-standing records and floods that have isolated outback towns and upended harvests. With national climate records showing a clear warming trend and experts warning that heavy rainfall events are likely to intensify in many regions, emergency planners and residents alike are bracing for more summers that bring fire, heat and flood — sometimes within a matter of weeks.