There has already been an increase in the various characteristics of heatwaves (such as severity, frequency and duration of heatwaves) in many regions across Australia. This increase in extreme heat observed in Australia is projected to continue with further increases global mean temperatures. Observed heatwave events have substantial impacts on human health, economy, infrastructure and the natural environment. Heatwave impacts also affect people differently. Globally-focused studies have demonstrated that the poorest countries are, in general, most vulnerable to future projected changes in heat extremes. Urban centres are of particular concern for extreme heat, both due social factors such as the large number of people located in urban areas globally and due to structural factors including the enhanced concentration of heat in urban areas (the urban heat island, UHI) compared to rural areas

In this study, we focus on future extreme temperatures in Australia and examine extreme heat in Sydney. We examine geographic variations in extreme heat across Sydney in climate observations and high-resolution climate model data for the present day and future time periods. Next, we examine the relationship between extreme heat and various socio-economic factors using HILDA (Household, Income and Labour Dynamics in Australia) survey data. Using these multiple datasets, we show that the greatest heat exposure is associated with the greatest socio-economic vulnerability in Sydney.