Grain preservation is essential for global food security, yet post-harvest losses remain high due to poor storage conditions such as excessive temperature, humidity, and gas accumulation. This paper presents a Hybrid Grain Monitoring and Alert System that provides a low-cost, energy-efficient, and sustainable solution for real-time environmental monitoring in grain storage. The system, built around an ESP32 microcontroller and DHT22 sensor, continuously tracks temperature and humidity, comparing them with predefined safety thresholds. When abnormal conditions are detected, it triggers both a local buzzer alert for offline notification and a real-time mobile alert via the Blynk IoT platform. Powered partially by solar energy, the system ensures continuous, eco-friendly operation. Experimental results confirm its effectiveness in reducing spoilage risks and improving reliability compared to traditional manual or high-cost automated systems