About Pilot Heatwave Forecast

About this product

The Heatwave Forecast is a set of graphical maps of heatwaves, severe heatwaves and extreme heatwaves for the current day extending out for the next four days.

Why were these colours chosen?

The yellow colour chosen for heatwave to allow for the warmer colours of orange and red to indicate rising severity. The changes in colour satisfy the Vision Australia recommendations for colour blindness.

What is a heatwave?

Three days or more of high maximum and minimum temperatures that is unusual for that location.

Until the introduction of this new Pilot Heatwave Forecast there was no national definition that described heatwave or measures of heatwave severity.

What is heatwave severity based on?

Every location across Australia has its own unique climatology of heat. The bulk of heatwaves at each location are low intensity with local communities expected to have adequate adaptation strategies for this level of thermal stress. Less frequent, higher intensity heatwaves are classified as severe and will challenge some adaptation strategies, especially for vulnerable sectors such as aged or the chronically ill. Even rarer and exceptionally intense heatwaves are classed as extreme and will challenge many normally reliable sectors, including power and transport infrastructure and anyone who does not adopt protective adaptation strategies.

What is heatwave intensity?

Heatwave intensity is a function of the maximum and minimum temperature over a three-day period and how this relates to climatology at every location, including how this function has changed over the last thirty days.

In other words the heatwave intensity identifies unusually hot conditions sustained for three days. The service also considers conditions over the preceding thirty days to include the degree of acclimatisation which may exacerbate or ameliorate the significance of the heat.

What will the Pilot Heatwave Forecast look like?

The Pilot Heatwave Forecast will consist of a panel of five maps across Australia for days 0 (today) to day 4. Each map will show areas where Heatwave conditions are forecast to occur and will also indicate whether their intensity is expected to reach Severe or Extreme status.

Each map examines conditions over a three-day period but consecutive maps help indicate Heatwave conditions persisting for many days.

The Map shows areas affected by heatwave, severe heatwave and extreme heatwave. What are the differences between these levels of severity?

Areas of Heatwave are described in yellow and within these areas higher categories of Severe or Extreme Heatwave may be described.

Areas of Heatwave can expect unusually hot conditions sustained for three days. The level of heat expected is unusual but injury to people is not generally expected unless inappropriate activities are conducted or sensible precautions are not are undertaken.

In areas of Severe Heatwave vulnerable people are at risk of injury.

Areas of Extreme Heatwave are likely to cause impact across multiple areas such as infrastructure, transport, energy, agriculture and both healthy and vulnerable people are at risk of injury.

Why a pilot service?

The science behind the service is robust and can be applied anywhere across the globe.

The service is a pilot in the sense that it is not fully integrated with the Bureau's other forecast and warning services at this early stage. This means that there will not be guaranteed notification of heatwaves within other forecast products, and the product may not be available in the event of a system malfunction.

There is opportunity for users to give feedback. Helping to inform and assist the Bureau in working towards a routine service proposal.

Who will benefit from this Pilot Heatwave Forecast product?

Heatwaves have a range of economic and planning impacts across a broad range of sectors, namely healthcare, energy, agriculture and emergency services. This includes reducing mortality and injury to people.

A range of knock-on effects ranging from loss of power, to disruptions to transport and critical infrastructure, have a significant economic impact on business, industry and people. With longer lead times, allowing for better planning, these impacts can be mitigated.

Australia is a hot country so why do we need a heatwave service?

Severe and extreme heatwaves have taken more lives than any other natural hazard in Australia's 200 year history. For example, during the 2009 Victorian bushfires, 173 people perished as a direct result of the bushfires, however 374 people lost their lives to extreme heat in Victoria in the heatwave before the bushfires.

How can people use this service?

This service will give people advance notice of unusually hot conditions allowing government, emergency services and people time to adjust and to adopt measures to reduce the impact.

Why have heatwaves been described as a 'silent killer'?

Heatwaves are not associated with violent weather such as tornadoes, cyclones or severe thunderstorms.

Heatwaves can result in significant stress on vulnerable people. This stress may result in death during the heat event but in many cases this can occur well after the cessation of the heatwave.

Often the cause of death during a heatwave is difficult to determine with many people who succumb often having pre-existing conditions.

Is climate change a factor in an apparent increase in the number and severity of heatwave events?

Climate projections show that extreme heat events are expected to occur more often and with greater intensity in the future.

When does a heatwave end?

Heatwaves finish when temperatures fall to more normal levels.


The maps provided by the Pilot Heatwave Forecast will reduce severity level or remove the indication of heatwave before the heatwave ends. This occurs because the maps are calculated across a three-day period. If the temperature is lower on the last day(s) then the map will indicate a lower risk despite unusually hot conditions being present for the first day or two.

Users are strongly recommended to monitor actual temperature forecasts for their location to understand when cooler conditions are expected to commence and therefore when the heatwave will finish.

Frequently Asked Questions

Am I affected

It is prudent to prepare and modify your behaviour when extreme heat occurs. You may be more vulnerable to severe heat if you are over the age of 65, particularly if you have pre-existing medical conditions. It is best to consult your doctor is you are unsure.

I am on the edge of the heatwave area. Do I need to take precautions?

Predicting heatwaves is not exact due to the variations in forecast temperatures that can occur. If the heatwave forecast map shows you are close to a heatwave you may still experience the same conditions and should plan accordingly.

I am on the edge of the heatwave area. Where do I get more information on the areas affected?

You can go to the Bureau of Meteorology's website www.bom.gov.au/australia/

How much advance notification will I get?

The Pilot Heatwave Forecast provides information for the next four days.

Where can I get advice on how to protect myself from the effects of extreme heat?

Your own doctor or local health authorities understand extreme heat and can provide appropriate advice.

Does this mean we will have a bush fire?

Bush fires are triggered by a range of factors. Heatwaves affect the dryness of the fuels, increasing this hazard but it is only one factor.

Where can I get more information?

I have lived through heatwaves before – why is this different?

All that has happened is that the Bureau has been able to create a forecasting tool to predict when and where heatwaves can develop in order to help you take precautions and be better prepared.

Will electricity services be at risk in a heatwave?

This is more a question for your electricity supplier but blackouts are more prevalent in severe and extreme heatwaves.

If we are having a heatwave does that mean the maximum temperature is going to be very high?

Heatwaves are more complex than just the daily maximum temperature. The minimum temperature is extremely important as well. If the minimum remains high then the subsequent maximum will occur earlier in the day and remain near that high temperature for a longer period. A higher minimum also restricts the amount of recovery due to less opportunity to discharge heat.

Why do we need a heatwave forecast?

Research has shown that heatwaves can increase deaths and health problems dramatically. By predicting when a heatwave will arrive it warns people, especially the vulnerable, to make precautions in advance and therefore prevent deaths. It will also help others like those who work outside, planning a family trip, etc.

I am a vulnerable person and don't have internet access. Is there any way I can get a personal notification of an impending heatwave?

At the moment there is no such service although this might be developed in future. In the meantime look in the newspapers, and listen to the radio or get a friend or relative with internet access to keep an eye on our website.

Is there a legal level after which I don't have to work in heatwave conditions?

Such regulations that exist vary. The new heatwave prediction is a new indicator and carries no such capacity to warrant legislative requirements.

What precautions should I take?

Guidance on protection from heat is available from your local doctor or Department of Health.

Future Developments

Following the 2013/14 summer the Pilot Heatwave Forecast maps evaluated for accuracy. A workshop with health and emergency sector stakeholders will consider the relevance of these forecast maps and how a comprehensive heatwave warning system should be developed.

Pilot Heatwave Forecast Feedback

We invite your feedback about the Pilot Heatwave Forecast.

We use information we receive to help guide revision and development of the product.

Feedback is reviewed regularly. If you have an issue that requires a response, please use the Bureau feedback form.

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