About the heatwave service

Is a heatwave coming?

Our heatwave forecast service runs from October until the end of March.

If a heatwave is headed your way, consider its severity level and listen to messages from your local emergency services and health authorities.

Heatwave maps

The heatwave service provides heatwave assessments, which identify heatwaves in the preceding days, and heatwave forecasts, which predict those about to occur.

The maps use colour coding to show the three different heatwave intensities, so you can see what conditions are heading your way.

The pale yellow colour indicates the lowest level of heatwave, while the warmer colours of orange and dark orange indicate rising severity.

Heatwave Assessment

The Heatwave Assessment consists of two maps for the previous two three-day periods. Each map shows the location of heatwave conditions, and the level of intensity. The map is accompanied by text describing the conditions.

Map: Example of a heatwave assessment map and text

Heatwave Forecast

The Heatwave Forecast consists of five maps for the next five three-day periods. Each map shows areas where heatwave conditions are forecast and the intensity they are expected to reach.

Map: Example of a heatwave forecast map and text.

Calculating the heatwave forecast

Heatwaves are calculated using the forecast maximum and minimum temperatures over the next three days. This information is compared to what would be considered hot for that location, and also to the observed temperatures over the last 30 days.

This calculation considers people's ability to adapt to heat. For example, the same high temperature will be felt differently by residents in Perth compared to those in Hobart, who may not be used to the higher range of temperatures experienced in Perth.

Similarly, if there has been a period of relatively cool weather in your location, then a sharp and sustained increase in temperature, this will show up in the heatwave forecast.

This means that in any one location, temperatures that meet the criteria for a heatwave at the end of summer will generally be hotter than the temperatures that meet it at the beginning of summer.