13 July 2022 2 minute read

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Bask in the shade of a leafy tree

Heatwaves are a reminder of how crucial urban trees are in our towns and cities. In fact, by planting trees strategically across urban areas, the air can be cooled between 2ºC - 8ºC.

In 2022 alone, the UK has faced record breaking temperatures of over 40ºC and a number of heatwaves. Due to our changing climate, more intense heat and weather conditions will continue to increase across the country, with specific implications for towns and cities as they become ‘urban heat islands’.

What's an Urban Heat Island?

Urban heat islands are when a built up area is much hotter than the surrounding countryside, particularly at night. This occurs when the high levels of concrete, pavements and buildings in towns and cities absorb and retain the heat from the day, creating localised warming and making it even hotter for city dwellers.

With 80% of the UK population living in an urban area, that means the majority of us will continue feeling the direct effects of these weather conditions and urban heat islands!


Cities are warming 29% faster than rural areas according to a new study from the World Economic Forum.

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The difference in shade between a tree lined lane and an open sunny field!


Lucky for us, trees are a great way of reducing the effects of urban heat islands.

They absorb water and then release it as water vapour through their leaves in a process called evapotranspiration, which produces a cooling effect.

Trees also provide shade for the ground and buildings, resulting in further cooling and less energy usage. It’s actually reported that trees properly planted around buildings can reduce air conditioning needs by 30%.

Urban trees also store less heat and energy than many artificial surfaces found in metropolitan areas such as concrete and asphalt.


As the climate crisis continues to escalate, it’s time to act now, invest in nature based solutions and plant more trees in built up urban areas! Trees for Cities is dedicated to improving lives and wellbeing by planting trees in cities. We work directly with inner city communities and those who have little or no access to trees as we believe everyone has a right to enjoy the many benefits urban trees bring.

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deaths attributable to the urban heat island effect during the summer could be avoided if trees covered 30% of urban space according to a new study published by The Lancet.

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Tree leaves help with the evapotranspiration process


watering cans

That's how much water a young tree needs a week to grow healthily, but they could do with more during periods of extreme heat. You can lend a helping hand to your local trees and plants during heatwaves by giving them a GOOD water. Make sure you water either early morning or late evening to minimise evaporation.

Learn more

Donate to Trees for Cities and together we can help cities grow into greener, cleaner and healthier places for people to live and work worldwide.