We built an open-source tool to find a city’s worst ‘heat island’ hotspots
We present URSUS_UHI, a new open-source software tool that helps urban planners automatically find the most unfavourable areas in a city: the places with the highest temperatures and the least green space.
In the fight against climate change, cities are on the front lines. The “Urban Heat Island” (UHI) effect—where cities are significantly hotter than surrounding rural areas—is a major threat to public health.
We all know the solution: more green infrastructure, like parks and trees. But for a city planner with a limited budget, the question is: where do we start? Which neighborhoods need help most?
In our 2025 paper in the journal SoftwareX, we present our answer: a free, open-source software tool called URSUS_UHI.
🧐 The problem: planners need a map, not just raw data
A city planner can’t just guess. They need a reliable, data-driven map to pinpoint the most unfavourable areas—the places that suffer from the double-whammy of extreme heat and a critical lack of vegetation.
Getting this map is hard. It requires gathering satellite data for temperature (LST), measuring vegetation (NDVI), combining it with expert knowledge, and running complex spatial data mining analyses. This is often beyond the technical capacity of many municipal planning departments.
💡 Our solution: URSUS_UHI, an “expert in a box”
We decided to build a tool that does all the heavy lifting. URSUS_UHI (URban SUStainability software for detection of Unfavourable areas due to the UHI effect) is an intelligent decision support system that encapsulates this entire complex process into one easy-to-use tool.
A planner or engineer can use this software to: 1. Load satellite data for their city. 2. Let the tool automatically run its spatial data mining process. 3. Instantly get a “Disadvantaged Area Index” (DAI) map that clearly identifies the priority zones.
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🛠️ How it works: spatial data mining + expert knowledge
The software’s “brain” is a data mining process that we developed based on our previous research. It doesn’t just look at heat or greenness in isolation; it intelligently combines them, incorporating expert knowledge about what truly makes an area “unfavourable.”
It processes the remote sensing data to automatically detect and classify the areas that need the most urgent attention.
🔬 Why does this matter?
This isn’t just a research paper—it’s a usable, open-source tool.
We’ve made a powerful data science methodology accessible to the people who can actually use it. Now, any urban planner or landscape engineer, anywhere in the world, can download URSUS_UHI and get an objective, data-driven map to help them decide where to build new parks and plant trees. It’s a practical tool to help make our cities cooler, greener, and more sustainable.
📖 The full paper and software
For the complete technical details of the software architecture and the data mining process, you can read the original open-access article in SoftwareX.
URSUS_UHI: URban SUStainability software for detection of unfavourable areas due to the Urban Heat Island effect. Authors: Francisco Rodríguez-Gómez, José del Campo-Ávila, Domingo López-Rodríguez, Luis Pérez-Urrestarazu. Journal: SoftwareX (vol. 29, 101997)