Australia Weather News

Kalgoorlie experienced a record-breaking six-day hot streak. - ABC

It is not just Perth feeling the exceptionally early burst of spring warmth, with central parts of Western Australia sizzling in record-breaking heat this past week.

On Saturday Kalgoorlie posted six consecutive September days above 30 degrees Celsius for the first time since records began, including a maximum of 36C on Friday.

Bureau of Meteorology spokesman Neil Bennett said the "unusual" heat smashed the city's previous record.

"Previously they'd had three consecutive days as their record for days above 30 and that was September 27, 2014.

"The reason for [the heat] was a large area of high pressure out over South Australia which was slow moving and dragged down some very warm air from the north-west of the state, so from the Pilbara and the Gascoyne, down in towards the Goldfield's area."

Kalgoorlie's mean maximum this month is currently 27.2C — well above its long-term average of 22.3C.

Perth is also experiencing a warm start to spring.

"At the moment Perth is like much of southern WA — above average. We're currently sitting [more than] two degrees above average," Mr Bennett said.

Last Monday Perth posted its second-highest September temperature since records began, as warm northerly winds pushed the mercury to 33.1C.

Although it is not unusual for Perth to experience bouts of heat during spring, Monday's maximum was exceptionally high for the start of the season considering the city's September average is 20.3C.

A sign of things to come

The spring outlook favours a hotter than usual season for Western Australia, which does not bode well for the upcoming fire season.

"For the spring period in terms of temperatures, we're expecting them to be generally above average, I don't think that there is anything on the horizon to suggest anything else," Mr Bennett said.

"The rainfall though, it's almost like a cut through the state where southern parts would suggest that the odds favour drier-than-normal conditions.

"Whereas up in the north, particularly as we go toward the back end of spring moving into November, there is a suggestion that the odds are starting to favour average to maybe above average rainfall.

"But that's some way off yet."

Given a number of intense bushfires have already ravaged parts of New South Wales and Queensland, authorities in Western Australia are on high alert.

"We have had a very early start to the fire season in New South Wales and Queensland but the outlook for WA is also suggesting that we could see some elevated fire risks during our summer as a result of some persistent rainfall deficiencies across south-west WA," Mr Bennett said.

"That area has experienced its driest start to the year, followed by the seventh-driest autumn on record.

"We're now also seeing some quite warm and dry conditions through the beginning of September and that's going to lead to increasing dryness of the soil and stress in the vegetation as well.

"So as a result of that, there is an expectation that above-normal fire conditions will exist for the southern parts through to the Esperance plains and even across into the Nullarbor.

Mr Bennett cautioned people against getting complacent after recent mild summers.

"I think the real message is that we've had two relatively quiet fire seasons but the conditions are there for above-normal fire weather conditions for the summer," he said.

"So I think people really do need to start thinking about their fire plans and what they're going to do."

A cool shock to the system

Given the balmy conditions so far this spring, a quick cool change mid-week could be a shock to the system for those living in the southern half of Western Australia.

The maximum is forecast to plummet to just 17C in Perth on Thursday and range in the low- to mid-teens throughout much of south-west WA.

"It will seem very cold and there's a little bit of rain to come as well which is a good thing … the amounts of rain we're expecting out of it aren't a huge amount, but some welcome rain nonetheless."

The wintry burst of weather is courtesy of a frontal system which will pass the south on Wednesday.

"Once the cold front moves through we get into an area of cold air in behind it [on Thursday] and if it's a fairly deep southerly flow which it is behind this one then the air is coming from a long way south.

"The temperatures down in our southern oceans are still very low."

But the cooler change will be short lived with temperatures bouncing back up by the weekend.

Perth forecast

  • Tuesday:Partly cloudy, 12–23
  • Wednesday:Showers increasing, possible rainfall 3–6mm, 12–22
  • Thursday:Shower or two, possible rainfall 0–1mm, 9–17
  • Friday:Partly cloudy, 5–19
  • Saturday: Mostly sunny, 7–22
  • Sunday:Sunny, 8–25
  • Monday:Sunny, 10–28
  • ABC