The presented abiotic parameters were measured during a lab experiment on the direct interaction effect of temperature and CO2 at low food conditions on Atlantic herring larvae, Clupea harengus L., over 32 days in Kristineberg (Sweden) in 2013. The performance of herring larvae was studied in four treatments resulting from the crossed design of two temperatures, 10°C vs. 12°C, and two CO2 levels, ambient 400 vs. elevated 900 µatm pCO2. The data set was used to describe temperature, pCO2 and pH over time and to calculate pCO2 from total alkalinity and dissolved inorganic carbon.