NSW Department of Planning and Environment

Urban heat

What is urban heat?

Average temperatures in large cities are 1 °C to 3 °C higher than in rural areas, as urban areas tend to trap more heat than natural environments. These higher temperatures can have a negative effect on human health and wellbeing, economic productivity, the environment, and infrastructure and services.

Some urban communities are more vulnerable to higher temperatures because of the ‘urban heat island’ effect. The western suburbs of Greater Sydney are particularly vulnerable to the urban heat island effect – temperatures in this region are sometimes 10 °C higher than in eastern Sydney on days of extreme heat.

What is an urban heat island?

Urban heat islands happen when an area has hard, sealed surfaces and less green infrastructure (such as tree canopy, vegetation, and waterways). This is because hard surfaces absorb, store and radiate heat, while green infrastructure reflects heat, provides shade, and releases water into the atmosphere. Green infrastructure also makes local areas easier to enjoy and encourages people to spend time outdoors. It also provides habitat for animals and plants and increases their variety in cities.

While climate change is increasing average temperatures across NSW, urban heat and the urban heat island effect are increasing the heat-related effects of climate change in urban areas. This makes increased temperatures and extreme hot weather events more severe and difficult to manage.

Planning how we will use land plays an important role in reducing urban heat vulnerability. It helps create places and communities that are more liveable and resilient to a changing climate. We are committed to delivering several planning initiatives aimed at reducing urban heat.

What are we doing?

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Greening our City is a NSW Government’s priority that aims to increase the tree canopy and green cover across Greater Sydney by planting one million trees by 2022.

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Increasing tree canopy cover in urban areas helps mitigate the urban heat island effect, creating cooler and more liveable communities.

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The Greening our City Grant Program supports local councils across Greater Sydney to increase urban tree canopy in local parks, streets and neighbourhoods.

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Throughout 2021–22, the NSW Government and our partners are greening the Great West Walk. More than 26,000 trees will be planted to provide shade, beauty, and cooler temperatures.

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Partnerships play an important role in helping us deliver the Greening our City NSW Government’s priority. These partnerships will deliver greener places and great public spaces and help create healthier, happier, and more resilient communities.

More information

The AdaptNSW website gives more information on urban heat and the heat island effect, as well as strategies for mitigation and case studies.

The Greater Sydney Commission’s Pulse of Greater Sydney 2020 report gives information on urban heat and the value of green infrastructure.

NASA has resources for children on urban heat.

Western Sydney

Find out more about urban heat in Western Sydney and what we are doing to achieve cooler and more liveable cities.

Find out more about urban heat in Western Sydney from The Australia Institute’s Heat Watch report.

Find out more about cooling Western Sydney – a study on the role of water in mitigating urban heat in Western Sydney.

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