Everyone feels it - our cities are getting hotter.

Millions of people are increasingly suffering from frequent heatwaves and the design of our cities is intensifying the problem - with the most vulnerable often the worst impacted.

A new digital solution from Arup – UHeat – has helped us to explore the issue in greater detail than ever before.

Our resulting ‘Urban Heat Snapshot’ reveals how the urban heat island (UHI) effect is pushing up temperatures in cities like London, Madrid, Mumbai and Los Angeles.

The snapshot highlights how:

  • temperatures can vary significantly from neighbourhood to neighbourhood
  • proximity to nature and vegetation is hugely important
  • poorer neighbourhoods are more likely to experience higher temperatures
  • employing machine learning and satellite imagery can help identify areas suffering most acutely and model interventions



expected increase in number of cities exposed to heat above 35°C by 2050


estimated number of deaths in Europe associated with extreme heat in 2022




increase in tree cover in European cities could have prevented over 2,500 excess deaths

Urban Heat Snapshot
Creating the snapshot - taking the temperature from the sky

Snapshot insights

The Urban Heat Snapshot analysed the temperature in the urban centres of nine cities: Brisbane, Cairo, London, Los Angeles, Madrid, Melbourne, Mumbai, New York and Singapore.

Urban Heat Snapshot
The snapshot revealed that Madrid had the most severe UHI - 8.5C hotter than its rural surroundings, that the hottest spots had less than 6% vegetation cover - whilst the coolest had over 70%, and that three of the cities experienced their worst UHI during the evening.