Key messages
- Research is important to understand extreme heat and heatwaves and how they affect communities.
- The department has funded several projects on extreme heat.
- Two heatwaves - in January 2009 and January 2014 - have been reported on.
- In January 2009, the Chief Health Officer reported that there were an estimated 374 excess deaths in Victoria during the heatwave.
- In January 2014, the Chief Health Officer reported that there were an estimated 167 excess deaths in Victoria during the heatwave.
Research continues to be an important part of understanding the health impacts of extreme heat and heatwaves on the community. The department has commissioned several research projects associated with heat.
Temperature thresholds for rural Victoria
Following on from the research for a heat alert system for Melbourne, the department commissioned Monash University to examine whether similar thresholds exist for the rest of Victoria.
A heat health threshold is defined as the temperature above which illness and death increases above a baseline level. The thresholds vary depending on:
- geographic location
- demographic profile of the community
- other vulnerability factors.
Temperature thresholds associated with increased mortality in ten major population centres in rural Victoria, Australia provides information about the adverse health effects of high temperatures in small regional towns in Victoria, and the results of the threshold temperature analysis.
Adaptive capabilities in older people during extreme heat events in Victoria: a population survey
In 2011, the department funded a population survey that included 500 telephone interviews of older people to identify the adaptive capabilities of older people in Victoria during periods of extreme heat.
The survey found that, overall, most older people changed their behavior on a hot day, such as wearing cooler clothing and increasing fluid intake. However, a small number reported that they did not change their behavior in response to hot weather.
Heatwave January 2014
The health impacts of the January 2014 heatwave in Victoria report found increases in:
- emergency department presentations
- Ambulance Victoria responses
- heat-related presentations during the week of the heatwave, (621, which was higher than the 105 expected); this represents a five-fold increase
- the Chief Health Officer reported that there were an estimated 167 excess deaths during the heatwave (858, compared to the 691 that were expected during the week of the heatwave)
- other emergency service and health services responses.
Although maximum temperatures for the January 2014 heatwave were slightly lower than those observed during earlier heatwaves, including 2009, mean temperatures were high and the heat lasted for a longer time. Victoria experienced the hottest 4-day period on record.
Maximum temperatures were 12 °C or more above average across much of Victoria, with parts of the state recording temperatures of 45 °C or more on three consecutive days during the heatwave. Melbourne experienced temperatures in excess of 41 °C each day between 14 and 17 January 2014.
Heatwave January 2009
A report by the Chief Health Officer - January 2009 Heatwave in Victoria: an Assessment of Health Impacts - found that there were an estimated 374 excess deaths during the January 2009 heatwave.
During 27-31 January 2009, Victoria experienced extreme temperatures, with many records set for high day and night time temperatures, as well as for the duration of extreme heat. Statistics include:
- Maximum temperatures were 12--15 °C above normal across much of Victoria.
- The temperature was more than 43 °C for three consecutive days 28-30 January, reaching a peak of 45.1 °C on 30 January.
- Melbourne experienced three consecutive days of temperatures above 43 °C, and little overnight relief.
Reviewed 18 September 2023