The digital technology plays a vital role for improving student learning and engagement. This is especially true in STEM education where teaching scientific concepts for K-12 education requires engaging platform to encourage inquiry-based learning, and it has been shown that the use of computer simulations can increase student achievement and their interest in STEM. In this paper, we present an interactive cloud-based web system that enables teachers in middle schools to effectively teach earth and environmental science using interactive simulations. To achieve on-demand accessibility and high reliability, our system is hosted on Amazon Elastic Compute Cloud platform that allows users, with an Internet connection and a Web browser, to access the course and do assignments. Additionally, we demonstrate teacher-role's functionality regarding managing course content, identifying low-performing students and achieving improved student learning outcomes. With the seamless integration of interactive simulations, user-friendly interfaces and transparent functionalities, our system aims to make learning more fun and engaging. Teachers who have used our system found it to be very helpful in engaging their students.