Cities around the world are struggling with environmental pollution. The conventional monitoring approaches are not effective for undertaking large-scale environmental monitoring due to logistical and cost-related issues. The availability of low-cost and low-power Internet of Things (IoT) devices has proved to be an effective alternative to monitor the ambient environment. Such systems have opened up environment monitoring opportunities to researchers and citizens while simultaneously confronting them with challenges like sensor accuracy, accumulation of large data sets, and data analysis, which itself is a formidable task that requires extensive computational resources and technical expertise. To address this challenge, a social, open-source, and citizen-centric IoT (Soc-IoT) framework is proposed that combines tools for real-time environmental sensing with an intuitive data analysis and visualization application. Soc-IoT has two main components: (1) CoSense Unit – a resource-efficient, portable and modular environment monitoring device intended for citizen sensing and complementing official environment monitoring infrastructure, and (2) exploreR – an intuitive cross-platform data analysis and visualization application that offers a comprehensive set of tools for systematic analysis of sensor data without any coding requirement. Developed as a proof-of-concept framework to monitor the environment at scale, Soc-IoT aims to promote environmental resilience and open innovation by reducing technological barriers.