Abstract: Hazardous accidents associated with the complex environment of underground gassy mines has urged researchers to constantly monitor mine environment for improved safety. The previously developed wireless monitoring systems for mine environment are not only expensive but also do not use the latest tools for operational management and information sharing. Our system aims to integrate Arduino-based sensors, Internet-of-Things (IoT), and cloud computing for near real-time mine environment monitoring, ventilation control, emergency communications and information sharing in a more synchronous and cost-effective way to significantly enhance underground mine safety. The web 2.0 based main server integrates probabilistic theory and spatiotemporal data analysis techniques for ambient intelligence. This system has been validated in an actual working environment of an underground coal mine. The data comparison for one week of CO, CH4, and CO2 Arduino-based sensors to their counter commercial equivalents demonstrated high accuracy and excellent performance in the harsh mine environment. The overall response of the proposed system showed 87.5% sensitivity and 77.7% positive prediction value. This system is open-source and cost-effective and can effectively contribute to expressively enhance mine automation and control with early detection and warning.