Monitoring programme of the Dutch Ministry of Infrastructure and Water Management to improve the understanding of dynamics and trends in ocean acidification parameters in the Dutch sector of the North Sea. This dataset (version 2023.10) contains all measurements from all batches of analysis up to and including October 2023 for which auxiliary variables (temperature, salinity and nutrients) were available from Rijkswaterstaat at the time of publication, specifically, 982 measurements of dissolved inorganic carbon, 981 of total alkalinity and 983 of pH, from 22 January 2018 to 22 March 2023. This dataset is a replacement for the previous version (v10; doi:10.25850/nioz/7b.b.tc). All data that appear in both this and the previous version are identical except for 49 DIC measurements which have been adjusted by up to 3 ?mol/kg due to an improved calibration and 3 measurements of nutrients which have changed almost negligibly due to updated auxiliary data from Rijkswaterstaat.