While sun and fun go together in many people's minds, it's important to know that heatwaves are Australia's most deadly natural hazard.
We issue heatwave warnings to help Australians prepare and stay safe.
Understanding heatwaves and how we warn you about them could save your life.
1. A heatwave is more than one hot day
A heatwave is when both the minimum and maximum temperatures are unusually hot for 3 days or longer. While some days might have a higher maximum temperature than normal, it's not a heatwave if it cools down to normal at night.
2. There are 3 types of heatwave
Heatwaves are categorised at 3 intensity levels:
- low-intensity heatwaves - these happen frequently during summer and most people can cope with them
- severe heatwaves - these are likely to be more difficult for vulnerable people such as older Australians
- extreme heatwaves - these are rarer and are a problem for anyone who doesn't take steps to keep cool.
3. Heatwave temperatures vary by location
Australia is a big country with a range of climatic conditions so heatwave isn't a one-size-fits-all proposition. As well as the expected temperatures, our heatwave forecasts consider what temperature is hot for the location and the temperatures over the previous 30 days. This allows for how you adapt to heat, depending on what temperatures you're used to.
As an example, the same temperature feels different to residents of Darwin and Hobart. A 37 °C day feels hotter to people in Hobart since they're used to cooler temperatures.
This also means that it takes higher forecast temperatures to reach the heatwave threshold by the end of summer than it did at the start.
4. Heatwaves affect many areas of our lives
They don't just challenge our comfort and health. They can cause problems for the agriculture, transport and energy sectors. This can cause flow-on effects - affecting everything from food to air conditioning.
5. Heatwave warnings help you prepare
We issue warnings for severe or extreme heatwaves. The warnings alert you that a heat hazard is expected within the upcoming 4 days. They also tell you expected temperatures, the timing and duration of the heatwave and which towns and communities will be affected.
You can see any active heatwave warnings on our Warnings and alerts page or through the BOM Weather app.
