Australia had its eighth-warmest year in 2023, marked by an unusually hot winter, three record-breaking dry months and excess rainfall and flooding.
The national mean temperature was almost one degree warmer than average, with the 2023 winter months the warmest on record or 1.53 degrees warmer than average, according to the Bureau of Meteorology.
States and territories also experienced significant rain swings, as tropical cyclones brought downpours across the Northern Territory, Queensland and northern Western Australia in early and late 2023.
This contrasted with unusually dry weather in some southern areas, with August to October emerging as the driest months on record.
In the oceans, sea surface temperatures in the Australian region were the seventh-highest on record.
The spring El Nino and Indian Ocean Dipole contributed to a drier-than-average spring.
Weather records were broken in almost every state and territory as communities were slammed with wild swings between cyclones, flooding rains, heatwaves and extreme fire conditions.
Millions of Australians also sweltered through weeks of stifling humidity, with east coast cities more humid than the long-term average for January, and Sydney registering its highest dew point on record.
A Climate Council report says the Australian summer has delivered clear signs the planet is overheating, including rising ocean temperatures along the east coast.
Sea surface temperatures have been more than 3C above average in some areas and strong easterly winds have brought unbearable humidity and weather conditions conducive to storms.
Biological scientist Lesley Hughes said Australia could no longer rely on historical weather records and patterns to make forecasts.
"Climate change is causing erratic swings from sweltering heat to devastating downpours, and it is increasingly hard to predict what each season will bring," she said.
"What we can rely on is the science ... that has been warning us for decades that days like these would come."
The unusually early arrival of Cyclone Jasper in Queensland and its slow dawdle across land resulted in enormous rainfall dumps - another sign of what's expected of intense storms on an overheating planet, along with high-intensity rainfall and above-average temperatures.
The council's director of research Simon Bradshaw said the chaotic summer weather had left many Australians suffering climate whiplash as they were hurtled from one extreme to another with little time to recover - and it was not over yet.
"From intense heat and fierce fire conditions to flooding rains and back again - the stifling humidity, intense storms, soaring temperatures and other extremes of recent months are all key signs of a fast-warming planet," he said.
The council said the weather was not foreseen, with a predicted El Nino and an early start to the fire season, which included a deadly Queensland blaze in October that destroyed more homes than the infamous 2019-20 Black Summer fires, indicating the nation was in for a hot and dry summer.
But it did not last, with extreme downpours, intense storms and flooding claiming lives and homes in communities up and down the east coast a month later, as some weather stations registered their highest November rainfall on record.
Temperatures have also been well above average in many parts, with homes around Perth threatened three times by large fires as the state baked through its warmest September in more than a century and a series of heatwaves broke records.
Towns in the Pilbara and outback Queensland also recorded new January temperature records, with maximums just shy of 50C.
Globally, it was also the warmest year on record, with sea ice at an all-time low.
