Neighbourhoods close to green parks and bodies of water are cooler throughout the year, finds a new UCL study focusing on the east of London, which also showed that low-cost weather sensors could provide usable research data in areas lacking climate data.
The research, published in Meteorological Applications, showed that east London neighbourhoods located around the Olympic Park were hotter by 0.53C than the park itself on average, and as much as 0.87C during the summer. This reinforces the understanding that urban planning that incorporates parks and water bodies can help mitigate some of the warming in cities.
These findings were made using measurements taken by low-cost commercial temperature sensors that are most often used to monitor greenhouses.
Although these are generally regarded as less accurate than scientific-grade sensors, the researchers wanted to see if these kinds of low-cost sensors could produce research-quality measurements in hopes of filling in data-collection gaps across the city using lower-cost options.
The individual sensors tested by the team typically retail at about €335 each (£291). Though more expensive than a consumer backyard thermometer, they're far much more accurate, while still cheaper than research grade temperature sensors which can cost thousands of pounds.
The researchers found that overall the sensors provided good quality and useable data, which could be used to understand heat exposure across different neighbourhoods
The most accurate results were obtained during summer nights, they found. During the winter months the data accuracy was somewhat lower and results would need to be more carefully considered, they added. In addition, though the sensors were fitted with shields to block the sun, direct sunlight also affected their accuracy, they found.
The team carried out their study for a full year, from June 2024 to June 2025, after verifying the accuracy of the sensors against a higher-rated weather station.
They used a total of 39 sensors spread across four locations in East London, including the Olympic Park, Hackney Wick, Fish Island and Park View Mansion. Each location had a cluster of between five and 12 low-cost sensors set up in the area.
Lead author Dr Oscar Brousse (UCL Bartlett School Environment, Energy & Resources) said: "Our work confirms the well-established fact that green parks and bodies of water help to keep cities cooler and neighbourhoods located further from these infrastructures tend to be warmer.
"But the most important outcome of this study is that we show that there are affordable ways for confirming that this is the case.
"Scientific monitoring of the local climate of cities is essential but often expensive, and our research shows there are viable, low-cost options for measuring urban outdoor temperatures, economically."
Cities are complex environments, and the local characteristics of different areas can lead to significantly different climatic conditions.
In order to inform urban design strategies to respond to rising temperatures, deploying adequate temperature sensors across our cities can help identify which areas are warmer and in need of intervention, and what characteristics can help to keep areas cooler, the researchers said.
Co-author Dr Clare Heaviside (UCL Bartlett School Environment, Energy & Resources) said: "Though cities like London are densely populated, there are significant areas with little or no climate monitoring, known as 'sensor deserts.'
"This is especially the case in more deprived neighbourhoods. In many ways these are the areas that need monitoring the most as many people there have less agency to adapt to warmer temperatures from climate change."
The research was supported by internal funds from UCL, Wellcome, NIHR and NERC.
