This dataset consists of hourly continuous measurements of pH, partial pressure of carbon dioxide (pCO2), salinity and temperature were collected at the University of Texas Marine Science Institute Research Pier, Aransas Ship Channel, TX, Gulf of Mexico from 2016-11-08 to 2017-08-23 using a SeaFET (pH), SAMI-CO2 (pCO2), and YSI (temperature and salinity) sensors. To reduce the maintenance cost and effort for sensors deployed in warm water that experiences intense biofouling, the sensors were set up to measure in situ seawater from an ex situ position. Water was pumped from approximately 1 m below the sea surface into the bottom spigot of a cooler that housed the sensors. To allow water outflow, a 1-inch hole was drilled at the opposite side of the spigot near the top of the cooler rim. The pump was programmed to turn on 20 minutes before each hour, pumping more than enough water to fully flush the cooler, and sensors recorded measurements on the hour. The YSI sonde was deployed directly into the Aransas Ship Channel inside a 2-inch PVC pipe at approximately 1 m below the sea surface. Funding for sensors and sensor deployment came from United States Environmental Protection Agency's National Estuary Program via the Coastal Bend Bays and Estuaries Program Contract No. 1605.