Prosper in a dynamic world
Search

Yet another round of heat to scorch southeastern Australia

Summer is officially here, with the mercury will soar into the low 40s across parts of southeastern Australia, including several capital cities. 

A prolonged period of northerly winds are being caused by a blocking high pressure system in the Tasman Sea and an approaching broad low-pressure trough. These winds will carry a hot air mass towards southern and southeastern Australia in the coming days. 

Image: Forecast 850 hPa temperature and wind at 5pm AEDT on Thursday, showing northerly winds dragging hot air towards southern and southeastern Australia. 

The burst of heat will impact SA and Vic on Thursday, before spreading east on Friday and into the weekend. 

Adelaide is forecast to see three days above 30°C beginning on Wednesday, with the heat set to peak on Thursday with 38°C on the cards. Nightime temperatures will also make it difficult to recover from the heat, with minimums forecast to be in the low 20s for three nights beginning Wednesday. 

Meanwhile western and northern SA will see temperatures soar into the low to mid 40s on Thursday and Friday before the cooler change flushes the heat out. 

Image: Maximum temperature forecast for Thursday, December 5, according to ECMWF 

While not as extreme, Vic will also be hot with temperatures forecast to reach the high 30s on Friday. 

Melbourne should endure two consecutive 33° C days on Thursday and Friday, with the temperature only dropping to the low 20s on Friday evening.  

Then the heat will creep to the northeast into NSW and Qld, with temperatures 3 to 9°C above average in the capital cities this week: 

  • Temperatures in western Sydney will reach the mid 30s on Friday and Saturday. 
  •  Sydney Observatory Hill should peak at around 33°C on Saturday.  
  • Sydney’s minimums should be above 20°C for three nights beginning Thursday.  
  • Brisbane will then see temperatures reach 34°C on Sunday. 
  • Brisbane’s minimum only dropped to 23.7°C early Wednesday morning, with another warm night forecast tonight. 

The heat across eastern Australia will also be coupled with extremely humid conditions, making the temperature feel 2 to 4°C hotter than the actual temperature in Brisbane and Sydney later this week.  

Looking ahead, temperatures should be cooler early to mid-next week ahead of another warm spell forecast at the end of next week. 

DTN APAC supplies precise weather intelligence to over 75% of the National Energy Market (NEM); and is the trusted provider for the Australian Energy Market Operator (AEMO).

Weatherzone’s next-generation nowcasting and forecasting system, OpticastTM, is independently proven to outperform other industry models, allowing energy traders to respond rapidly to changing conditions. From 14 day forecasting to seasonal outlooks, you have access to complete and powerful weather intelligence giving you the confidence to make the best call.

Meeting the needs of the changing market, Weatherzone utilises high-resolution modelling and local knowledge to provide 5-min granularity observations and forecasts, optimising your market bidding and maximising your profits. These, coupled with briefings from our energy meteorologists, give you full awareness of the associated risk.

Benefit from specialised indices such as apparent temperature, Cooling/Heating Degree Days (CDD/HDD) and Effective Degree Days (EDD) to help accurately predict demand. You can get a clear picture of forecast conditions across the market and quickly assess heat/heatwave potential from 14 days out to 12 months

No matter where your energy trading focus lies, we have the power generation and weather insights to inform your critical decisions, keeping you ahead of the curve. For more information please visit our website or email us at sales.apac@dtn.com.

 

Latest news

Satisfy your weather obsession with these news headlines from around the nation, and the world.

El Niño Is Here: What a Potential Record Event Means for Southeast Asia and Australia

  El Niño was officially declared in June 2026, raising the prospect of widespread impacts across Southeast Asia, from extreme heat and water shortages to higher energy demand and agricultural stress.   The World Meteorological Organization has warned countries to “prepare for it to be severe”, while several global forecast models suggest the event could rank among […]

How El Niño will shape Australian port operations in winter-spring 2026

Australian ports and marine pilots can expect a season of shifting wind and swell patterns through winter and spring 2026, as a developing El Niño brings the likelihood of drier conditions and more variable operating windows across the country’s coastline.  Will El Niño develop in 2026?  There are clear signs that an El Niño pattern is becoming […]

From Kimberley to northern NSW: Bushfire outlook flags risk for resources sector this winter

Bushfire risk doesn’t usually make headlines in June, but AFAC’s winter seasonal outlook is putting mining and resources operators on alert from the Kimberley to the NSW.  Australia’s official seasonal bushfire outlook for winter 2026 was released by AFAC on Thursday, May 28. The outlook predicts increased fire risk across the northern parts of the Great Sandy Desert and surrounds […]

The signal was there weeks earlier: forecasting one of the year’s biggest wind events

In mid-May 2026, DTN APAC meteorologists flagged a strengthening Southern Ocean pattern in model guidance, signalling an extended run of record-challenging wind conditions across the NEM.  Nearly three weeks later, NEM wind generation climbed from around 1.5GW to more than 9GW, supplying roughly one-third of the grid and coming within 1GW of the all-time generation record.  The event highlighted […]