How your suburb’s lack of trees could be affecting your health

It’s a blisteringly hot afternoon in Seddon in Melbourne’s inner west, and cafes are closing their doors against the 3pm heat.

There are few street trees on Charles Street. Where there are trees, they’re sparsely planted, relatively young and, in the heat of the day, offer little shade. Temperature tests conducted by The Age reveal that while the air temperature is 35 degrees, the footpath measures a scorching 53.1 degrees.

Surface temperatures in Seddon on Charles Street (left) and Victoria Street.Credit: Bianca Hall

Around the corner on Victoria Street, trees on the median strip and footpath are better established and offer some welcome shade. Here, the footpath is over 18 degrees cooler, measuring 34.5 degrees.

Suburb-level satellite mapping compiled exclusively for The Age shows just 4 per cent of Seddon has natural shade – one of the lowest rates of canopy cover in Greater Melbourne.

Satellite imagery produced by Dutch urban advisory group Cobra Groeninzicht, in partnership with RMIT University, shows a thin line neatly dissects Melbourne’s east and west.

From above, the west resembles a patchwork of hot and hotter urban heat islands, with some green patches offering respite (including Keilor, Avondale Heights and Maribyrnong, which have canopy cover of between 27 and 33 per cent).

The urban heat island effect, seen through infrared imaging, shows the difference in temperatures black roofs make.Credit: Sebastian Pfautsch

But the greener suburbs are the outliers in Melbourne’s west. Most suburbs roughly to the west of the Yarra River and Darebin Creek have less than 15 per cent tree cover – even when you take local parks into account.

Contrast this to the leafy east, which from above looks like a patchwork of soft and forest greens. In Park Orchards, for example, canopy covers 90 per cent of the suburb.

Satellite imagery tells a tale of two cities. Depending on where you live in Melbourne, temperatures can vary by up to 20 degrees. In suburbs like Seddon, surface temperatures can vary by more than 18 degrees within a few hundred metres.

The Victorian government has set a long-term target of 30 per cent canopy cover for the public realm, while the NSW government aims to lift canopy cover to 40 per cent by 2036.

Type your suburb in the interactive below and click on the outline to view the canopy cover in your area

But these targets seem a long way off. RMIT University urban planner Dr Thami Croeser, who helped compile the data for The Age, said a lack of tree cover has social, equity and health effects on residents.

“The major growth corridors in Melbourne’s west, north and south-east correspond quite closely to the dark red patches on our map, [while] old, well-established residential areas in the east that have historically stridently opposed development are the places with the best canopy cover,” Croeser said.

“This means that anyone trying to get relatively affordable housing, either with a new apartment or a lower-cost house far from the city, will not have much nature around them, and will swelter in heatwaves.”

Aerial photographs of emerging communities in Melbourne’s west demonstrate how heat islands are being built into growth suburbs. In Manor Lakes, 33 kilometres south-west of Melbourne’s CBD, grasslands are being cleared to make way for new housing.

The edge of the Manor Lakes housing estate shows a stark lack of canopy cover common in swaths of Melbourne’s west.Credit: Jason South

Most of the houses have been built to the fence lines, with dark grey and black heat-absorbing roofs on the homes and only a handful of trees in the estate. The only relief from the heat is inside air-conditioned houses.

Professor Sebastian Pfautsch, an urban management and planning expert from Western Sydney University, said developers were “moonscaping” natural landscapes to remove waterways, farms and vegetation for new housing developments in the growth corridors of Melbourne and Sydney.

Worse, the ever-increasing sea of black roofs and treeless landscapes was building in heat retention, he said.

“This is 2025, and I find it depressing that we’re still building like that.”

Professor Sebastian Pfautsch is an expert in urban heat.Credit: Wayne Harley

“In the years when you live in your house, you pay thousands of dollars in electricity excess. It’s bizarre. It really is bizarre.”

Hug a tree, save your life?

Scientists last year reviewed the health records of 104,000 Australians who had experienced cardiovascular events and fatal heart attacks over 10 years.

They found that when people’s health data was cross-checked against the total green space and tree cover they lived among, a 10 per cent increase in tree canopy cover was linked with reduced risks of all-cause mortality, cardiovascular disease mortality, and fatal or non-fatal heart attacks.

Charles Street, Seddon, baking in the summer sun.Credit: Luis Enrique Ascui

Not only do trees reduce air pollution, the study found, they also improve psychiatric, respiratory and cardiovascular health, promote outdoor physical activity and cool our cities.

While tree shade is lacking in outer-suburban growth corridors, the satellite imagery shows there are also some troubling heat islands in inner-city and formerly industrial suburbs like Richmond, Collingwood, Brunswick and Prahran, where apartments have sprung up.

Credit: Matt Golding

“If you’re somewhere like Eaglemont or Kew, which have good canopy cover, your backyards are probably doing a bit of work in keeping you cool,” Croeser said.

“But if you look at Collingwood or Fitzroy and Brunswick, it’s the trees on the streets doing the work because there’s no or very little backyard canopy or heat protection.”

Croeser sees the unequal access to nature in capital cities like Melbourne as aggravating inequalities associated with the housing crisis.

“We need to get much better at growing our canopy as we grow our housing stock, by designing new suburban streets better, and retrofitting existing streets much more substantially when we put in new apartments.”

According to Pfautsch, not only is it important to plant and nurture street trees – it’s crucial to plant heat and drought resistant species that can actually form crowns to protect us from extreme heat.

Projections have shown new suburbs with trees that offer 1 per cent canopy today would only provide 9 per cent canopy cover by 2040, because developers are often planting the wrong types of trees, he said.

The effects of tree shade on road surface temperatures, seen through infrared imaging. Credit: Sebastian Pfautsch

“These kinds of developments will never get to those canopy cover [targets set by state governments]. They will never have the shade, which means you will never have the people walking outside to the playground with their kids because it’s just too hot.”

In your own backyard, you can check the Which Plant Where tool.

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