21/09/2017 12:14 PM AEST | Updated 21/09/2017 12:14 PM AEST

Scorching Weekend Weather For Sydney, NSW Set For First Ever 40 Degree September Day

Serious 'Septemperatures' are coming. Yes, we just made up that word.

Reuters Photographer / Reuters
Even the sun's gonna get sunburn.

Here comes the heat, as spring gets serious for the first time and Septemperatures* sizzle.

Sydney, Melbourne, Adelaide and Brisbane are all going to see temperatures of 25 degrees or higher in the next few days, and a range of heat records for the first month of spring appear certain to be broken.

  • Sydney is going to feel particularly scorching this coming weekend. The city is forecast to reach 33 degrees on Saturday and 36 is forecast for Penrith and locations across the western suburbs;
  • The highest Septemperature ever recorded anywhere in the Sydney basin was 35.8 at Penrith (which last year we revealed as Australia's hottest suburb), so it looks like Sydney will set a heat record;
  • Elsewhere in NSW, the first ever 40 degree September day looks likely to happen in the state's north-west. The hottest ever Septemperature was 39.6 in Wanaaring, a tiny map speck which is quite literally situated out the "back 'o' Bourke". Bourke and surrounds is tipped to reach 40 on Saturday;
  • Brisbane will also be hot. Autralia's third-largest city is looking at two straight days of 35 from Sunday into Monday. The city's September record high of 35.1 could easily be broken.


Here's a nice graphic which illustrates the hot push of air from central Australia to the east coast.

By about Monday, things will be back to normal as some cooler air pushes in from the south. Melbourne should return to the mid teens and Sydney will be back in the low 20s.


There's not always a link. Weather fluctuates. That's why it's called "weather" and not "that same thing that happens every day". We've always had early heat outbreaks in spring.

But we do know that the warming atmosphere is making heat records far more likely than low temperature records. ANU climate scientist Sophie Lewis, who we profiled for our Breaking The Ice climate science podcast, has done some really terrific work on that.

The Climate Council also weighed in this week with its report "Hot And Dry: Australia's Weird Winter", which talked about increasing heat records, and the fact Australia's 2017 winter was 1.9 degrees warmer than usual in terms of average daily maximum temperatures.

Anyway the main thing you probably need to know if you're in Sydney this weekend, is that sea temps are currently around 18.4 at Bondi. They're more like 14.4 at St Kilda, so good luck if you're planning a bay dip to take advantage of the 25-degree day forecast for Melbourne on Saturday.

*We look forward to seeing the word "Septemperatures" in the Macquarie Dictionary soon.