This document provides an overview of notable developments in the field of informal STEM education (ISE) in 2018. It highlights select publications, data, resources, conferences, and other moments of significance to various sectors within ISE such as citizen science, cyberlearning/gaming, living collections, making/tinkering, media, libraries, museums/science centers, youth programs, and science communication. The document is intended to inform stakeholders about growth and opportunities within the field.