Background: How weather impacts injury

Over the past three decades, extreme weather events have increased in frequency and severity (IPCC 2014, State of the Climate 2022: Bureau of Meteorology). 

There is increasing awareness of the impacts of climate change on human health (MJA 2021). Some of the changes in the natural environment affecting Australia’s health and welfare are detailed in the Natural environment and health report.

In 2021–22, there were 2.4 hospitalisations per 100,000 Australians for injuries caused by forces of nature, which includes natural disasters, lightning and extreme weather, but excludes bushfires. Injuries caused by forces of nature also led to 0.2 deaths per 100,000 in 2020–21 (Injury in Australia).

Weather factors can increase the risk of injury in multiple ways:

  • extreme weather events such as storms and flooding, and bushfires (a hazard exacerbated by extreme weather events) can cause physical injury and death
  • sustained adverse weather conditions are associated with an increase in the risk of intentional self-harm and assaults
  • adverse conditions increase the risks associated with regular activities, such as heat stroke during sporting activity.

Scope of this report

This report reviews currently available data about injuries caused by extreme weather conditions or related hazards, specifically:

  • Extreme heat
  • Bushfires (a natural hazard associated with extreme heat)
  • Rain and storm-related events, including high rainfall, floods, cyclones, and storms
  • Extreme cold.

Extreme weather and natural hazards related to it can cause acute injuries as well as secondary or subsequent injury, such as traffic accidents due to road conditions. Identifying where weather directly caused injury can be challenging in currently available hospital and mortality datasets. This report suggests opportunities to develop weather-related injury surveillance systems and discusses limitations in the available data.

This analysis is limited to cases where it is reasonable to conclude injury was related to exposure to one of the four extreme weather-related conditions listed above.  

  • Causes of injuries may be multifactorial, but only the first recorded cause is considered in this report. This means injuries from road traffic accidents that occur due to adverse weather conditions are excluded due to the primary external cause of injury being recorded as transport.
  •  Available data does not preclude non-weather-related causes of injuries. For example, hypothermia is counted where there is exposure to extreme cold, but this may include cases where the exposure was swimming related.
  • Only acute injuries where hospitalisation or death occurs are counted.

These, and related caveats are discussed further in the section of this report titled ‘Limitations in ascribing injuries to weather’. Overall, this report presents an underestimate of extreme weather-related injuries. Injury definitions and codes used for this report are detailed in the technical notes section.