The SeaDataCloud Temperature and Salinity Historical Data Collection for the North Sea includes open access in situ data on temperature and salinity for the period 1893 – 2017. The data were retrieved from the SeaDataNet infrastructure at the end of October 2017. The dataset format is ODV binary collections [3]. The quality control of the data has been performed with the help of ODV software. Data Quality Flags have been revised following common recommended procedures defined under SeaDataNet 2 project [2] in conjunction with visual expert check. Trajectories (“underway” data) and “discrete” data (CTD, XBT, discrete water samplers) have been handled separately.