Weather across Queensland for the past two days has been "extremely unusual" for July, with much of the Sunshine State shrouded in a cold haze.
Senior meteorologist Harry Clark said the combination of rain and cool temperatures was strange.
"Both in terms of the amount of rainfall and the extent of it, for what is one of our driest months of the year, but also for the extremely low maximum temperatures we've seen," he said.
Brisbane recorded its coldest daily maximum temperature in two decades, reaching just 12.4C at around 1pm.
Brisbane's coldest-ever maximum was 12C, set in July 2000.
It was colder than Sydney, Melbourne, Adelaide and Hobart at one point on Tuesday, and only just warmer than Canberra.
To find the third-coldest July maximum you don't have to go digging in the archives — it was Monday's top of 14.2C, the seventh-coldest day on record.
Generally, temperatures have been eight to 12 degrees below average.
"Temperatures are looking more into what you might expect in Melbourne, or some of those southern capital cities where it's the typical winter weather," Mr Clarke said.
"For us [Queenslanders], it's certainly not, and it comes as quite a shock to the system."
Mr Clarke said many cold weather records were broken across Queensland overnight.
He said Rockhampton peaked at 12.5C on Monday and Toowoomba was a "stand-out" at 7.6C.
The Gold Coast Seaway also recorded its coldest day of any month ever at 14.2C on Monday.
Further north, Townsville recorded its coldest July day ever at 15.1C, and Mackay struggled to tip the mercury over 13C.
'A lot of moisture'
Some parts of Queensland also broke rainfall records, with Cairns and Mareeba experiencing their wettest July days on Monday.
Mr Clark said there was widespread rainfall of 50 to 80 millimetres across the east coast in the past 24 hours, with comparatively less in central parts.
"It's really significant rainfall for July," he said.
"The rain is now starting to shift eastwards, so… into tonight, we will see that rainfall start to move off the east coast, with just a few lingering showers into Wednesday for south-east Queensland."
Mr Clark said the unusual rainfall was the result of a north-west cloud band, which typically occurs when the western parts of the Indian Ocean become colder than the eastern parts.
"That means a lot of moisture coming in from northern Australia and the Indian Ocean, streaming down over Australia from the north-west," he said.
"We're likely to see further rain events throughout the winter months across much of Australia, including parts of Queensland."
This comes in addition to the La Nina weather system that has brought widespread flooding to Queensland this year.
Mr Clark said there was a 50 per cent chance there could be another La Nina event in the upcoming summer months.
"In saying that, it is quite a way out until we get to summer, so there's still a lot of uncertainty, but even if it doesn't form, we are still looking at favouring wetter-than-average conditions.
"With saturated soil conditions and full dams after the last two years, that certainly is a bit of a concern and watch point going into the next few months and indeed into the summer."
