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.

Rapid El Niño signal accelerating risk for Australian businesses

El Niño–favourable conditions are gathering pace across the tropical Pacific, with key ocean indicators approaching threshold levels and early atmospheric responses emerging.  While uncertainty remains around final El Niño strength, historical analogues show that even weak events can generate widespread impacts, including reduced rainfall, warmer daytime temperatures, increased frost risk, elevated fire danger, reduced tropical cyclone activity, and more. Industries including […]

Australia’s 2025–26 Cyclone Season: Slightly Above Average, Dominated by Severe Systems

Australia has just experienced a highly impactful tropical cyclone season, with more than 60% of systems reaching severe intensity, causing widespread disruption and damage to communities and multiple industries across northern Australia.  The 2025–26 Australian tropical cyclone season officially ran from 1 November 2025 to 30 April 2026. During this six-month period, Australia saw 11 tropical cyclones, with nine […]

What does a ‘super El Niño’ mean for Australia’s businesses?

There are signs that a very strong, or ‘super’ El Niño could develop in the tropical Pacific Ocean later this year. So, what does this mean for Australia’s weather during the second half of 2026? El Niño on the horizon The tropical Pacific Ocean is currently in a neutral state, meaning neither El Niño nor […]

How does DTN help businesses monitor bushfire induced pyrocumulonimbus thunderstorms that ignite more fires?

Intense heat from bushfires during elevated fire danger days can trigger fire-induced pyrocumulonimbus thunderstorms that ignite additional fires. In early January 2026, an extreme heatwave sweeping over southeastern Australia brought catastrophic fire danger to Victoria. Intensely hot bush and grass fires spread erratically and quickly in hot, dry and gusty winds, with pyrocumulonimbus generating lightning, […]