Purpose Cultural heritage archives rely on environmental monitoring devices, such as dataloggers or more complex networked systems, to ensure collection preservation through collecting temperature, humidity, light and/or air quality measures. Existing systems are often costly, inflexible and do not use a modern, internet of things (IoT) approach. This paper aims to determine the suitability of currently popular general-purpose IoT devices, standards and technologies to the environmental monitoring needs of archivists, as well as identify any challenges. Design/methodology/approach This paper describes an exploratory study detailing the design, construction and usability testing of a do-it-yourself datalogger and data dashboard system, which seeks to manage previously identified trade-offs in cost, required technical skill and maintainability. Findings The environmental monitoring system presented met archivists’ needs well and was generally noted to be easy-to-use, efficient and an improvement on existing systems. This suggests that an IoT approach can support archivists’ needs in this area. Research limitations/implications Potential limitations of this study include lack of archival staff with sufficient technical training to maintain such a system and the rapid pace of IoT evolution yielding unstable and constantly changing technologies. Practical implications The system design presented in this work provides a blueprint for cultural heritage organizations desiring a fuller-featured, lower cost environmental monitoring system for archival collections. Originality/value This research takes a novel user-centered, open-source, IoT approach to construct an environmental monitoring system that is designed directly from archivists’ requirements and is extensible for future needs.