Eastern states shivered through a chilly June, is a warmer winter still on the cards?

Australia Broadcast Center

a day ago

It is now two weeks past the winter solstice, and despite a prediction of a warmer winter, many Australians have been feeling the cold.
Large parts of the country have shivered through sub-zero temperatures and there have been big dumps of snow and powerful storms.
So, have temperatures been significantly cold, or has the country become acclimatised to milder winter temperatures?
A look at overnight minimum temperatures, which typically occur first thing in the morning, indicates days have started particularly chilly in many parts of Australia.
The Bureau of Meteorology's temperature anomaly map shows most of the country experienced "cooler than average" minimum temperatures for June, apart from southern WA, western South Australia and northern Queensland.
Daytime maximum temperatures, however, were closer to average for most of the country, apart from WA, which was warmer than normal.
BOM climatologist Qian Zhou said the cold mornings had made it New South Wales's coldest June in nearly 20 years, by minimum temperature, while Queensland had its coldest June minimums in over a decade.
"In June, several cold fronts passed us through the south and south-east with cold air behind it," Ms Zhou said.
"And after the cold front passed, high-pressure systems settled in, creating the clear skies and the light winds overnight, allowing heat to escape.
The cold minimum temperatures included -10 degrees Celsius in Goulburn, in the New South Wales Southern Tablelands, on June 21, which was colder than some sites in Antarctica.
Canberra had three mornings in a row below -7C, a record cold run for the city.
Tasmania also saw some particularly cold mornings late in the month, with Liawenee plunging to -9C, while Queensland's typically mild weather was freezing on several occasions.
While the frigid mornings have warranted a scarf and beanie, they have been far from remarkable by historical standards — with the month coming in as the 48th coldest June on record.
"Although the minimum temperature in June across Australia was below average, it was not that remarkably low compared to history," Ms Zhou said.
Barely more than a handful of sites with more than 20 years of data broke daily cold records.
Ms Zhou said record cold temperatures were becoming less common because of climate change.
Since 1910, Australia's average temperature has warmed by more than 1.5C, with most of that change occurring since the 1950s.
It means all seasons are getting warmer on average.
The last "colder than average" winter, for example, was more than a decade ago.
While cold extremes have become rarer, warm extremes have been getting more common, according to Ms Zhou.
"And there has been an increase in number of extreme heat events.
"A big part of this is due to global warming."
The exception was for extreme cold nights in parts of south-east and south-west Australia, where the frequency of frost had been relatively unchanged since the 1980s.
Ms Zhou said this was because those regions were also facing a rainfall decline during the cooler months, resulting in more time under clear skies and more "heat loss from the surface" — just like this year.
The official winter outlook strongly favoured warm days and nights for June for almost the entire country.
June was warmer than average for maximum temperatures. So, in that case, the outlook was accurate.
But for the minimum temperatures, the outlook showed strong odds of warm minimum temperatures and for most places, that did not eventuate.
Ms Zhou said it demonstrated how individual weather events, which were not able to be detected in the long-range outlook, could change the outcome of a month or season.
"The long-range forecasts are unable to predict individual weather events more than one or two weeks in advance," she said.
"Those weather systems are short timescales, but the long-range outlook is providing a forecast of the overall trend for the season.
"In June, there were at least two major cold fronts with cold outbreaks, which brought abnormally cold air to much of the country and particularly to the east, which the long-range forecast was unlikely to be able to resolve at a long lead time."
Technically, though, the outlook can not be wrong because it is not declaring what will happen, but just presenting the odds.
Even though there was an 80 per cent chance of it being warmer than average, there was still a 20 per cent chance of it being colder than average.
In this case, the outside chance won.
Just because June was cold, it does not mean the rest of winter will continue that way.
You only need to look to last year as an example.
Frigid temperatures in June 2024 saw many calling it the "coldest winter in living memory" and criticising the BOM for getting their forecast wrong.
But by the end of August, it was Australia's second-warmest winter on record.
The Bureau of Meteorology has softened its forecast for the rest of this winter though.
For the most part, it is still expected to be warmer than normal for July and August.
But what was a fairly emphatic signal of warmth for the entire country is now looking more patchy, depending on where you live.
Parts of South Australia are now expected to have cooler-than-average minimum temperatures in July, though maximum temperatures are still expected to be above average for most.
And by August, large parts of inland Australia are showing even chances of above- or below-average maximum temperatures — meaning it could go either way.
As for rainfall, July is forecast to be average to below average for most places, apart from coastal NSW, which is expected to be wetter than normal.
This changes in August, with rainfall largely favoured to be above average for most of the NT, Queensland, NSW and parts of South Australia.