Makkah’s Grand Mosque marble stays cool in peak summer due to solar reflectance and layered insulation/Image: SPA
Anyone who has walked barefoot around the Kaaba in peak summer knows the feeling. The sun is relentless, the air heavy with heat, yet the marble underfoot does not burn. In a place where temperatures regularly climb past 45°C, that small detail leaves many quietly puzzled.The courtyard surrounding the Kaaba is paved with high-quality, light-coloured marble widely identified as Thassos marble. This dolomitic stone is known for its high solar reflectance and low heat absorption coefficient. Rather than absorbing and storing solar radiation like darker paving materials, it reflects a significant portion of incoming sunlight. As a result, surface temperatures remain markedly lower than materials such as concrete or asphalt, even under prolonged exposure to direct sun.Scientific research has examined this behaviour in detail. A 2022 study published in the Journal of The Institution of Engineers (India) Series D, titled Investigating the Unique Thermal Properties of Thassos Marble, analysed the thermophysical characteristics of the stone. Researchers found that Thassos marble demonstrates higher thermal conductivity than conventional white marble. This allows heat to disperse more efficiently through the material instead of accumulating at the surface. The study also highlighted that the marble’s microstructure and mineral composition enhance both reflectivity and internal heat redistribution.Complementing these findings, a 2021 peer-reviewed study titled Cool White Marble Pavement Thermophysical Assessment at Al Masjid Al-Haram, Makkah City, Saudi Arabia. Using local weather data and thermal modelling under real climatic conditions, researchers concluded that the marble’s high reflectance significantly reduces surface temperatures. The study determined that the use of cool white marble plays a critical role in maintaining safe and comfortable walking conditions for barefoot pilgrims.The cooling effect is reinforced by structural design. The marble slabs are thick and installed over specialised insulating layers and air-permeable spaces. This layered configuration enables heat to dissipate downward and sideways rather than remaining concentrated at the surface. The expansive open-air layout of the Grand Mosque allows continuous airflow across the courtyard, while the steady movement of worshippers contributes to ground-level air circulation.What appears to be a simple stone surface is, in reality, a carefully engineered thermal system. Through the integration of high-reflectance marble, enhanced thermal conductivity, layered insulation and architectural airflow, the Mataf maintains moderated surface temperatures in one of the world’s hottest urban environments.
