The agricultural sector frequently faces significant losses during the storage of perishable produce such as onions, primarily due to improper storage conditions. This paper presents a novel Smart Onion Storage System designed to enhance the longevity and quality of stored onions by employing Internet of Things (IoT) technology. The system utilizes IoT sensors to continuously monitor critical environmental parameters, specifically temperature and ethylene gas concentration, which are pivotal in dictating the storage life and quality of onions. Real-time sensor data is collected and transmitted to the ThingSpeak cloud platform, enabling remote monitoring and data analysis. Based on the sensor inputs, the system dynamically adjusts storage conditions. For instance, ventilation can be activated to reduce ethylene concentration or cooling systems adjusted according to the detected temperature. This automated, data-driven approach not only aims to reduce spoilage and economic losses but also contributes to sustainable agricultural practices by minimizing energy consumption through optimized storage management. Preliminary results indicate a significant potential in reducing wastage and enhancing the efficiency of onion storage facilities. The adoption of such IoT-based systems could revolutionize storage practices, ensuring freshness and reducing losses in the agricultural supply chain.