Adelaide's hot summer on hold with mild start to December forecast
Don’t pack away your cardigans – Adelaide’s mild weather is set to rain on summer’s parade, with an unusually cool start to the new season.
Summer is officially on its way, but if you think that means hot days and balmy nights – chill out.
Adelaide’s unusually cool spring is forecast to drag into the beginning of summer, with milder days and “scrappy, patchy” showers lingering until at least the middle of December, says The Advertiser’s weather guru Darren Ray.
“It’s not going to heat up in the first half of December,” says the respected meteorologist.
“There’ll be a continuation of the mild conditions we’ve been experiencing during spring.”
Mr Ray said the cool start to summer was being influenced by twin weather patterns – an Indian Ocean Dipole to the west of Australia and La Nina off the east coast – and high ozone levels over Antarctica that resulted in a ridge of tropical high-pressure systems lingering to the north of Adelaide rather than following their usual path and migrating south.
He said the higher ozone levels were caused by a big solar flare that occurred in late October.
But those influences were weakening and the weather would eventually start to warm up just in time for Christmas, with temperatures around 30C for the big day.
“There’s a lot going on but it does look like we’ll be in a warming-up phase leading into Christmas,” he said.
“There’ll probably be more days in the high 20s and low 30s as we get closer to Christmas.”
A rather cool 19C maximum is forecast for Adelaide for the first day of summer on Monday before the mercury does rise to tops of 30C and 31C on Wednesday and Thursday.
But the maximum will drop back to 23C again by Saturday.
Raylene Coates, who was catching up for a cuppa with friend Megan Quirk at Hawthorndene cafe Joan’s Pantry, said she was hanging out for warmer weather. It was a crisp 13C in the morning when they met.
“I’m a summer person and I feel like I’ve been let down by the weather,” she said. “Everyone’s waiting for some consistency of spring sunshine … 30C on Christmas Day would be beautiful – that’s what we need.”
Mr Ray added: “It’s tending to more average summer conditions in the second half of January to the end of February. There’ll be two or three relatively sizeable rain events during summer.”
The first half of January would return to fairly mild conditions before warming up heading into February, he said.
“I’m not seeing big heatwaves in the data,” he said.
“It’s tending to more average summer conditions in the second half of January to the end of February. There’ll be two or three relatively sizeable rain events during summer.”
November rainfall has already reached 72.2mm for the city centre – more than double the 31.1mm average.
The state’s reservoirs are at 68 per cent of capacity, up from 51 per cent at this time last year.
But despite the good spring rains, South Australia was still officially in drought, Mr Ray said.
And the state was heading for a warmer, drier autumn and winter in 2026, when an El Nino weather pattern looked likely to develop.
“Autumn will be a little bit warmer than average, a little bit drier than average – good conditions for getting late-crop tomatoes,” he said.
“That shift towards El Nino conditions could mean a hotter, drier spring (next year) heading into a dry summer, which would have a significant impact given we are still in drought.”
