A second heatwave in as many weeks is building across South Australia and has authorities planning for a spike in heat-related hospital admissions.
After four days above 40 degrees Celsius last week, similar conditions are expected from Friday to Monday, with Bureau of Meteorology state manager John Nairn describing the weather as quite unusual for December.
The impact of the ongoing drought and the late arrival of monsoonal rains across Australia's north, has left the continent bathed in very hot air and the land extremely dry.
"Dry soils mean you're not evaporatively cooling the air," Mr Nairn said.
"So without cooling rains across the north of Australia, we're seeing heat being redeveloped all the time,"
"It never escapes the continent, it just keeps on being developed."
Mr Nairn said there was also the prospect of more to come with heatwaves generally associated with January and February.
"We're actually building into the heatwave season, rather than peaking," he said.
South Australian Ambulance Service spokesman Chris Howie said that since the beginning of last week's heatwave paramedics had responded to 575 heat-related incidents with 266 people taken to hospital.
Figures are not yet available for whether any of those admissions resulted in deaths.
Mr Howie said that over the coming days the ambulance service would have extra crews on duty to cater for another spike in calls which was expected to continue into next week.
"The cumulative effect (of consecutive hot days) has more of an impact than the one isolated day," he said.
Adelaide was forecast to hit 40C on Friday with similar conditions to prevail until a cool change later in the day on Monday.
Top temperatures over the weekend have been pegged in the high 30s with the bureau saying a series of troughs should prevent a repeat of last week's record-setting highs including a 46C Day in the city.
But in regional areas, the mercury will go higher with many centres forecast to have tops around 45C over the coming days.
Monday is also expected to be a day of extreme fire danger across most of SA ahead of the cool change with strong winds forecast along with possible lightning especially in the mid-to-far north.
The looming heatwave has prompted the state government to declare a code red which provides for extra help for the homeless.
"During a code red, agencies across Adelaide will extend their daytime operating hours to ensure people sleeping rough are keeping cool and well-hydrated," Human Services Minister Michelle Lensink said.
