Australia bakes in heatwave

Adelaide's historic spring heatwave is nearing its end after more than a week of the mercury hovering above 35 degrees, but the relief will be short-lived and parts of NSW and Victoria are also bracing for a baking.

The city of churches has sweltered in daily temperatures above 35 degrees for the past eight days, with weekend sporting events cancelled, the state's open-range zoo closed to the public, and grass and scrub fires keeping the Country Fire Service busy.

Sunday's temperature is expected to hit 40 degrees, before cooling to 28 on Monday and then heading up again, to hit 41 degrees on Wednesday and Thursday.

Parts of western Sydney are also expected to reach 41 degrees by Friday, with Victoria's Mallee district enduring a forecast 41 degrees on Sunday and heading back up towards 40 degrees again by the end of this week.

Domenic Panuccio, meteorologist with the Bureau of Meteorology in Adelaide, says the city has endured three significant heat waves every year for the past three years.

"It's certainly been a lot hotter than usual in the last three years - perhaps it's part of a longer term warming trend," he said.

"This is the only spring heat wave on record for South Australia and our records date back to the late 1800s."

He said while a low pressure trough was passing over the state Sunday afternoon, it would only provide temporary relief.

"Enjoy it while it lasts because there's more heat to come through -- on Wednesday and Thursday we're forecasting 41 degrees with hot northerlies kicking in again."

A spokeswoman for the open range Monarto Zoo, east of the city, said it was closed to the public on Sunday due to the bushfire risk posed by the extreme heat.

SA Country Fire Service spokeswoman Karina Loxton said firefighters had been kept busy with a number of regional grass and scrub fires this weekend but they were all under control.

And a spokeswoman for the SA Ambulance Service said workloads had increased in recent days, which was probably in part due to the heat but she could not say to what extent.

Senior meteorologist with the Bureau of Meteorology in Victoria, Phil King, said the November daily average so far this year for Melbourne was nearly 30 degrees -- the warmest ever start to November.

"That's pretty much the case across all of Victoria and probably more so in northern Victoria," he said.

He said spring began with above average rainfall in Victoria, but from the start of November that had "just turned off like a tap" and there were few frontal systems moving across the state.

"It's been a remarkably sharp change in the patterns," he said.

- AAP