Profiles of salinity, temperature, turbidity, and particle size distribution were collected by the U.S. Geological Survey (USGS) Pacific Coastal and Marine Science Center in South San Francisco Bay. Data were collected at depth intervals ranging between 0.5 and 2 m (depending on total water depth); sensors remained at each depth for 1-2 minutes. Each profile was collected from surface to bed, and the near-surface region was sampled again at the end of the profile to check steady-state conditions. Profiles were collected on 4 days: June 22, July 21, and December 3 of 2021, and on January 4, 2022 (UTC). Data files are grouped by season (summer or winter) and by instrument (CTD or LISST). No LISST data were collected in the winter. Users are advised to assess data quality carefully.