The heat is on - Why Perth’s concrete jungle is cooking

If you walked past the corner of Mill St and St Georges Terrace in Perth at 2:30 PM today, you didn’t just feel the Perth summer, you walked into a heat trap, peak hotspot 72 degrees.

At Decarbonology, we believe data is the best way to visualise our changing climate. Today, we took a thermal imaging camera to one of the city's busiest intersections to see exactly how our urban infrastructure handles a 35°C day. The results were a stark reminder of why urban greening isn't just an aesthetic choice, it's a survival strategy.

While the thermometer recorded 35 degrees the ground told a much more dangerous story.

- Unshaded Pavement recorded 53.9°C – 56.2°C +21°C (Avg)

- Peak Hotspot (Mill St) 72°C +37°C

- Under Tree Canopy 32.7°C -2.3°C

The "Frying Pan" effect In the unshaded sections of the Terrace, the ground temperature was consistently 20 degrees hotter than the air. Most interesting, at the corner of Mill St, the thermal sensor peaked at a balmy 72°C. At these temperatures, pavement becomes a radiator, pumping heat back into the environment and making it nearly impossible for the city to cool down at night.

This is the Urban Heat Island effect in action, hard surfaces absorbing solar radiation and turning our streets into ovens.

The Power of 9%.

Unsurprisingly was the power of trees. Despite only having roughly 9% canopy cover in the study area, the ground temperature beneath the leaves was just 32.7°C. The more trees, the better the environment.

The Verdict. The shade from a single tree managed to keep the ground nearly 40 degrees cooler than the exposed asphalt just meters away.

Why this matters for Decarbonisation Every degree the ground heats up increases the energy demand for surrounding buildings as AC units fight to keep interiors cool. By increasing our urban canopy, we don't just make the city more walkable, we directly reduce the energy load and carbon footprint of our CBD.

The data from 15 January 2026, is pretty stark, who wants to be outside when the hard surfaces are overheating, but nature has the solution. We need to increase water cooling areas, greater shaded/ reflective areas and increase the tree canopy. See some of the photos.