This dataset comprises sea surface temperature measurements taken close to the time of high water at intervals of three to four days. The measuring programme consisted of approximately 50 observing sites around the shoreline of England and Wales and the data set spans the time period from 1963 to 1990. A few observing sites were already in existence when the network was established, for example observations at the Seven Stones and Varne Light Vessels go back as far as 1905. The Ministry of Agriculture, Fisheries and Food Lowestoft Fisheries Laboratory (MAFF), now known as the Centre for Environment, Fisheries and Aquaculture Science Lowestoft Laboratory (CEFAS) - part of the Department for Environment, Food and Rural Affairs (Defra), set up a database for these data, supplemented by both the earlier data and also by data from non-MAFF sources. Data from 1963 until 1990 are held at the British Oceanographic Data Centre (BODC). The time series is ongoing but data later than 1990 are not stored at BODC, these data are available from CEFAS.