The COOLCITY Index is a synthetic indicator of cities’ climate adaptation potential, used to assess the state of blue-green infrastructure in urban areas.

The COOLCITY Index platform is an annual dataset covering 11,041 cities in the European Union, assessing their adaptation potential based on the COOLCITY Index (CCI) and the five key adaptation challenge indexes. These indicators allow for city comparisons, identification of blue-green leaders, and highlighting regions facing the greatest adaptation challenges.

Our database is intended for anyone who wants to deepen their knowledge and make decisions based on reliable and objective data. It is dedicated to cities, decision-makers (at European, regional, and national levels), researchers, teachers, media representatives, NGOs, as well as anyone interested in the impact of climate change on cities and quality of life.

The entire process is based on satellite data. With it we create thematic maps of the urban environment. We then assess its condition by calculating a set of environmental indicators covering five key adaptation challenges: thermal conditions, water conditions, biodiversity, vegetation state, and surface permeability. These indicators are integrated into a single synthetic COOLCITY Index, which measures cities’ overall adaptation potential.

The COOLCITY Index is based on satellite data from the Sentinel-2 (ESA) and Landsat-8 and Landsat-9 (NASA) missions. These are used to develop thematic maps of the urban environment, which are then used to calculate COOLCITY indicators. The city database is supplemented with administrative, demographic, geographic, and climate data from publicly available sources such as EUROSTAT, IMERG, IPCC, and GloH2O.

City boundaries are determined based on administrative units (LAU), degree of urbanisation (DEGURBA), and population statistics (EUROSTAT). A city is defined as an urban area governed by a single administrative authority, with at least 5,000 inhabitants and a minimum area of 2 km² (except in metropolitan areas).

To be included in the COOLCITY Index, your city must have at least 5,000 inhabitants and cover a minimum area of 2 km². The detailed methodology for defining city boundaries can be found in the Methodology tab.

The COOLCITY Index is published annually on April 1st (starting in 2026) and covers data from the previous year. The analyses begin in January for the preceding year. Publication requires time to collect, process, and analyse the data to ensure its reliability and accuracy.

The LIFECOOLCITY project, titled “Use of remote sensing for management of blue-green infrastructure in the process of city adaptation to climate change”, is implemented under the LIFE Programme: LIFE-2023-SAP-CLIMA-CCA – Climate Change Adaptation, project no. 101074553. The project is funded 95% by the LIFE Programme and the National Fund for Environmental Protection and Water Management, while the remaining 5% is provided by the Consortium. The project runs from 2023 to 2029.