JSC 42 Report CoverThe report from the 42nd Session of the WCRP Joint Scientific Committee (JSC-42), held in June and July 2021, has now been published. The report includes a summary of the presentations from the WCRP Core Projects, Grand Challenges, and Lighthouse Activities, as well as an overview of key strategic discussions and the official list of actions and decisions of the Joint Scientific Committee. We thank all JSC-42 participants for their involvement in the Session and for their contributions to its outcomes.