Heatwaves are generally acknowledged as a period of unusual and uncomfortable hot weather that could negatively affect human health.

The Bureau of Meteorology defines a heatwave as occurring when the maximum and the minimum temperatures are unusually hot over a three-day period at a location. This is considered in relation to the climate and past weather at a location.

Extreme heat can affect everyone; however, some people are more vulnerable. Extreme heat can also affect infrastructure such as electricity supply, transport (roads and rail) and other services resulting in power outages, delays or cancellations of rail services or failures of traffic management systems.

Examples of significant heatwaves in Victoria include:

  • 2009 - consecutive days of temperatures above 43°C in late January followed by a record 46.4°C on 7 February culminated in the Black Saturday bushfires
  • 2014 - hottest four-day period on record, from 14-17 January 2014.

Both heatwaves resulted in widespread impacts on the health system, public transport disruptions and power outages. The former Department of Health and Human Services released the January 2009 Heatwave in Victoria: an Assessment of Health Impacts report covering the health impacts of the heatwave incident in 2009. 

All links in the table below will open in a new window.

Publish year Assurance activity Summary Organisation
2010 Report on Department of Health's January 2009 heatwave in Victoria: An assessment of health impacts (External link) A parliamentary committee appointed to inquire into and report on Victorian departmental and agency performance and operations of the year 2009 resolved to invite the Department of Health to give evidence at a public hearing with respect to the Department’s January 2009 Heatwave in Victoria: an Assessment of Health Impacts report. This report provides an overview of the Committee's public hearing with the Department in relation to its report, together with follow-up matters. Parliament of Victoria
2012 January 2009 Heatwave in Victoria: an Assessment of Health Impacts (External link) A report analysing the health impacts of the January 2009 Victorian heatwave. Department of Health and Human Services
2014 2014 Heatwave Management: Reducing the Risk to Public Health (External link) A report highlighting the significant community demand on ambulance services during periods of heatwave. In response to this report, Ambulance Victoria reviewed and updated the Heatwave Sub-plan in its all-hazards Emergency Response Plan. Victorian Auditor-General's Office