Greenhouse microclimate management remains a major challenge in arid and semi-arid regions, where strong diurnal temperature fluctuations and excessive humidity variations can reduce crop yield and quality. Conventional fossil-fuel heating systems are unsustainable, emphasizing the need for efficient solar-driven thermal solutions. This study experimentally evaluates a large-scale solar-heated greenhouse located in Chenchou, Southwestern Tunisia (33.888 degrees N, 10.097 degrees E), integrating water-based thermal storage and soil heat storage to regulate temperature and humidity. The results show that the system stabilizes night-time temperatures, maintaining internal air above 13 degrees C and reducing relative humidity by up to 15%, ensuring improved crop comfort. Daytime horizontal temperature gradients reached 9 degrees C at ground level and 5 degrees C at 2 m, with maxima at the greenhouse center, while night-time horizontal variations were limited to less than 3 degrees C. Vertical temperature distribution ranged from 12 degrees C near the soil to 21 degrees C at 2 m, with relative humidity varying between 25 and 35% at 2 m and 35-60% near the soil. Nocturnal heating produced localized thermal inversions near the water inlet, gradually attenuating along the flow path, whereas soil heat storage contributed to a uniform distribution of night-time temperatures, reducing extreme variations and enhancing overall microclimatic stability. These findings highlight the effectiveness of combining solar energy storage in water and soil, providing a sustainable approach to regulate greenhouse microclimate. This integrated strategy represents a significant advancement in sustainable greenhouse climate management, improving environmental stability, crop growth, and productivity under arid conditions.