Three-Year Study Across Guildford Provides Clues To Coping With Climate Change

Published on: 24 Aug, 2026
Updated on: 24 Aug, 2026

Sensor installation in green areas was a key part of the project. Picture: University of Surrey

Green and blue spaces, such as woodlands, grasslands and riversides, could provide a vital line of defence for cities facing increasingly hot summers, according to new research from the University of Surrey.

In a study published in Environment International, researchers monitored temperatures across Guildford for three years to understand how different urban environments cope with heat. They found that green and blue spaces were significantly cooler than built-up locations.

They describe the summer of 2026 as feeling “like a wake-up call” and say that as UK summers get hotter, the evidence of science can help us make better decisions.

The team compared six types of green and blue infrastructure – woodland, lakeside, grassland, a pocket park, riverside and a green wall. They then compared temperatures with a built-up area between June 2023 and August 2025.

During peak summer hours, all six of the green and blue sites were cooler than the built-up location. The woodland site recorded the greatest difference, at around 2.5°C cooler, followed by grassland at 2.3°C and lakeside at 2.1°C.

Across ten extreme heat events that were analysed during the study, the woodland site was on average 4.5°C cooler during the daytime than the built-up site, with differences frequently exceeding 5-6°C during the most severe heatwaves. Grassland and lakeside were around 4°C cooler on average.

The researchers, from Surrey’s Global Centre for Clean Air Research (GCARE) , also compared how often each location experienced heatwave conditions, defined in Surrey as temperatures reaching at least 28°C for three consecutive days.

Over the three summers, the built-up site experienced 54 heatwave days, with heatwave conditions accounting for 19.6 per cent of summer daytime observations. In comparison, all six green and blue spaces experienced significantly less extreme heat. The green wall recorded the highest exposure of the six at 8.7 per cent, while the woodland area recorded no heatwave periods at all.

Professor Prashant Kumar, Founding Director of GCARE at the University of Surrey and corresponding author of the study, said: “Summer 2026 has felt like a wake-up call for the impact of increasingly hot summers.

“We now have three years of evidence showing the difference nature can make. What was most surprising was the woodland site, where we recorded no heatwave conditions – compared with almost a fifth of summer daytime observations at the built-up location.

“There is no one-size-fits-all solution, but our findings show why trees, green spaces and water should be an important part of how we design towns and cities to cope with a warmer climate.”

As part of GCARE’s Guildford Living Lab, the study used a network of sensors to record temperature and humidity every minute at the seven locations across Guildford over three years, alongside satellite data to provide a broader picture of urban temperatures. Satellite observations also showed substantial differences in summer surface temperatures, particularly between the built-up, woodland and lakeside areas.

Soheila Khalili, postgraduate researcher at GCARE and lead author of the study, said: “After three years of monitoring these sites through ordinary summer days and intense heatwaves, it was striking to see just how differently they responded to the same conditions. As our summers get hotter, this kind of long-term evidence can help us make better decisions about the green and blue spaces we build into our towns and cities.”

The research team has cautioned that further studies are needed to verify the findings. These could examine multiple examples of each type of location and how their cooling effects extend into surrounding streets and neighbourhoods.

The work was supported through RECLAIM Network Plus, GP4Streets, GreenCities, GREENIN and University Global Partnership Network-funded projects.

The full paper can be found here: https://doi.org/10.1016/j.envint.2026.110452