Iranian Sustainable Building Scientific Association International Journal of Urban Management and Energy Sustainability 2538-1628 7 3 2026 07 01 Climatic Zoning of Iran Using the De Martonne Index as a Basis for Climate-Responsive Architectural Design 51 64 741467 10.22034/ijumes.2026.2097369.1392 EN Samaneh Foroughian Assistant professor, Civil Engineering and Architectural Department, Faculty of Engineering, University of Torbat Heydarieh, Torbat Heydarieh, Iran 0000-0003-2268-9219 Journal Article 2026 06 08 Climatic conditions are among the key factors influencing environmental planning, energy management, and the formulation of architectural design strategies. The De Martonne aridity index, which relies on the two variables of temperature and precipitation, is one of the empirical methods widely used for climate classification. This study aimed to classify the climate of Iran using the De Martonne index and to interpret the results from the perspective of climate-responsive architectural design. For this purpose, the mean annual temperature and precipitation of 201 stations across the country over a 30-year period were collected, and the De Martonne index was computed; the climatic classes and their spatial distribution were then determined and examined for their implications for architectural design. The results showed that 59% of Iran's area falls within the arid class and 34% within the semi-arid class, while 2% is semi-Mediterranean, 0.5% semi-humid, 1.5% humid, and 3% very humid. Arid climates dominate the east, south-east, north-east, and the Persian Gulf margin, whereas semi-arid climates prevail in the mountainous west, north-west, and south-west; humid and very humid climates are concentrated along the Caspian Sea. The prevalence of arid and semi-arid climates and the marked climatic contrasts between zones underline the need for climate-adapted architectural strategies including building orientation, solar-radiation control, opening regulation, natural ventilation, and reduced energy use and support the periodic updating of climatic zoning as a basis for climate-responsive design across Iran's different regions. https://www.ijumes.com/article_741467_64739511d1b7a58a5d25e6765de2ea36.pdf