LCZ

Local Climate Zones are an international classification of urban and natural land cover, implemented in France by Cerema’s satellite unit using very high resolution satellite imagery and open databases. The mapping, published on 20 May 2025, distinguishes 17 categories, 10 built and 7 natural, and covers 12,000 municipalities, 88 urban areas and 44 million inhabitants, with an extension to overseas territories. It is available free through a map viewer and for download on data.gouv.fr, with methodology guides. Its results: more than 5 million inhabitants live in areas highly sensitive to heat, more than 20,000 hectares of built land experience a strong or very strong heat island effect, and in cities with more than 400,000 inhabitants half of the population has high or very high sensitivity. It addresses PNACC 3 measure 13 on urban renaturation. The practical consequence: a local authority within this coverage already has a heat island map without needing to commission a study.