The goal of this annual report is to provide a review on the key activities and results of the GHRSST community in 2021. In 2021, the provision of high quality Sea‐Surface Temperature (SST) data from a broad satellite constellation has continued, with particular advances towards the continuity of microwave SST with AMSR‐3 planned for launch by JAXA in 2023/2024 on the Global Observation Satellite for Greenhouse gases and water cycle. There are exciting times ahead with further launches of several Sea Surface Temperature capable and specific missions coming up in the next few years, all adding valuable observations to the constellation. These include GOES‐T, JPSS‐2, MTG I1, Metop‐SG A1, Sentinel‐3C/D, FY‐3E, FY‐4B, plus others. (Read more in the PDF... ) Copyright 2022© European Union This report has been edited by the GHRSST Project Office. Funded by the European Union’s Copernicus programme. This copyright notice applies only to the overall collection of papers: authors retain their individual rights and should be contacted directly for permission to use their material separately. Editorial correspondence and requests for permission to publish, reproduce or translate this publication in part or in whole should be addressed to the GHRSST Project Office. The papers included comprise the proceedings of the meeting and reflect the authors’ opinions and are published as presented. Their inclusion in this publication does not necessarily constitute endorsement by GHRSST or the co–organisers. Cite as: GHRSST Annual Report 2021, DOI: https://zenodo.org/record/5824540