A 9-month aquarium experiment with the cold-water Dendrophyllia cornigera was conducted to investigate the single and combined effects of warming, acidification and deoxygenation on its ecophysiological response. The experiment took place at the Aquarium finisterrae (A Coruña, Spain), from the 6th of May 2022 to the 24th of February 2023. Treatment values for each parameter (current in situ vs. climate change) were: 12 °C and 15 °C (temperature); ~7.99 and 7.69 (pH); ~8.63 mg/L and 6.45 mg/L (dissolved oxygen concentration). A total of eight treatments (with 3 replicates each, 5 L aquaria) were set up. This dataset contains the registered values for temperature, pH, DO (% air saturation and mg/L) and sainity from the experimental aquarium over the course of the experiment. Temperature and DO were daily measured with a YSI ProODO dissolved oxygen instrument. Salinity was weekly assessed with a WTW 350i multiparameter device equipped with a ConOx probe. Measurements for pH were performed every 1 – 2 months. Samples for pH were directly collected on cylindrical 10 cm cuvettes and analysed on daily basis. After being thermostated at 25ºC, samples were measured using a manual spectrophotometrical procedure with a Sigma Aldrich impure indicator (Clayton and Byrne, 1993). The uncertainty of pH is about 0.005 pH units.