Cities worked together to summarize the most relevant information and actionable findings related to the latest science on 1.5°C. The Intergovernmental Panel on Climate Change (IPCC) Special Report on Global Warming of 1.5°C was produced by IPCC scientists – at the request of nations at the adoption of the Paris Agreement – to explain the pathways to and impacts of 1.5°C. A Summary for Urban Policymakers (SUP) produced by members of the SR1.5 author team also synthesized findings for cities. This briefing document was subsequently compiled by city policymakers to summarize the most actionable information for cities on the latest 1.5°C science.