In 2023, researchers found shade cooled Singapore streets by 0.8°C across 20 sites. Today, vegetation is estimated to save 228 GWh of energy yearly

Singapore's trees are doing more than adding greenery to the city. Research suggests that shade can make streets cooler for people, while vegetation around buildings may also reduce the energy needed for air conditioning.

In 2023, researchers studying Singapore’s one-north district, including Lei Xu and Ronita Bardhan through the Cambridge Centre for Advanced Research and Education in Singapore, found that shaded areas were about 0.8°C cooler than nearby sunlit locations across 20 paired sites.

The difference became more pronounced when researchers measured how heat affects the human body. Using the Universal Thermal Climate Index, which considers radiant heat, humidity and air movement, they found that shade reduced heat stress by an average of 3.1°C and prevented 92% of the extreme heat stress that would otherwise have been recorded.


A separate assessment points to a potential energy benefit. Using the InVEST urban cooling model, researchers estimated that vegetation-driven cooling could reduce energy use in public housing by about 228 gigawatt hours a year, with an estimated value of around S$47 million.

Shade can make streets feel much cooler

The 2023 study examined 20 paired sites in Singapore's one-north district during an August afternoon. Researchers walked the routes using panoramic cameras, thermal imagers and heat-stress trackers.

While the air-temperature difference between shaded and sunlit locations was about 0.8°C, the Universal Thermal Climate Index showed a much larger effect on heat stress.

Shade lowered the index by an average of 3.1°C and prevented 92% of the extreme heat stress recorded under unshaded conditions.

The finding highlights why air temperature alone does not capture how hot outdoor conditions feel. Radiant heat, humidity and air movement also influence the experience of heat.

Trees can also help cool buildings

The benefits of vegetation can extend beyond the street. Trees intercept solar radiation before it reaches building walls, limiting how much heat the structure absorbs.

The Cooling Singapore catalogue cites field research in Nigeria where an unshaded building's indoor temperature reached up to 5.4°C above outdoor conditions. A neighbouring building shaded by trees never exceeded 2.4°C above outdoor temperature.

The same catalogue cites simulations showing that vertical greenery on Singapore buildings could reduce cooling loads by roughly 10% to 31%, depending on the amount of facade covered and the density of the foliage.

Vegetation could cut public housing energy use

Researchers also assessed the open-source InVEST urban cooling model using Singapore data.

The model estimated that vegetation-driven cooling could reduce annual energy use in public housing by around 228 GWh. The estimated value was about S$47 million a year across roughly 11 million square metres of block footprint.

The estimate has a wide confidence interval, ranging from roughly S$28 million to S$66 million. The 228 GWh figure is a modelled estimate rather than a direct measurement of electricity savings.

Singapore's humidity limits the cooling effect

Trees are not a complete answer to urban heat, particularly in Singapore's humid climate.

Evapotranspiration, through which plants release moisture and cool the surrounding air, is less effective when the atmosphere is already close to saturated.

Very dense vegetation can also restrict airflow, potentially leaving streets more humid and allowing pollutants to accumulate.

That is why combining different forms of shade can be more effective than relying on trees alone.

The one-north study found that combining tree canopy with structures such as bus shelters and overhangs performed better than either approach by itself. Trees can block sunlight while allowing air to move, while solid structures provide shade but can also restrict the breeze.

Researchers estimated that well-shaded stretches could achieve cooling of around 3°C to 5°C, although creating that level of shade through planting alone could take decades.

Singapore continues planting more trees

Singapore is also continuing to expand its tree cover.

The National Parks Board launched the OneMillionTrees movement in April 2020, with a goal of planting one million additional trees and taking the national total beyond eight million. The baseline planting rate was around 50,000 trees a year, meaning the target requires roughly twice that pace for a decade.

Smaller green spaces can also have a measurable local effect. In March 2026, NUS researchers reported that a microforest outside City Square Mall, covering roughly the area of a basketball court, cooled its immediate surroundings by up to 5°C. The site also recorded around 70% more species than a nearby grass patch.

Trees offer more than shade

Singapore's research points to a broader role for urban vegetation.

Tree canopies can make outdoor spaces more comfortable while limiting the amount of solar heat reaching buildings. In turn, that can reduce cooling demand.

The findings do not suggest that trees can eliminate Singapore's urban heat or replace other cooling measures. Instead, they show how vegetation can work alongside structures such as shelters and overhangs to reduce heat in a city where space is limited.

What looks like an ordinary patch of shade can therefore have effects that extend from the pavement to a building's energy use.