A dataset is presented for defining real-time CO2 frost formation in a vertical packed column. ECT could estimate the internal permittivity distribution of the sensing area through boundary measurements. The ECT system used in this work includes sensors, data acquisition system and a computer with imaging software. The excitation signal is a sine wave with 14 Vp-p and 200k Hz frequency. One measurement electrode is chosen for excitation; other electrodes are used to acquire the signal separately. The frame rate of the ECT system is 714 frames per second. The temperature of the bed material is recorded using thermocouples and data loggers, the thermocouples are inserted into the capture column from the top of the column and are adjusted to an appropriate height above the horizontal mixed gas injector. Using the thermocouples above and below the ECT sensor helped to estimate when frost formation would be occurring within the region of bed material that the ECT sensor was measuring. The presence of this plateau in the temperature profiles identifies that CO2 frost is forming within the bed and has reached an equilibrium. We include data of ECT capacitance and temperature during the whole progress. It was found that the temperature, packing material and component of mixer gas all effect the ECT measurement. This dataset could be used to withstand extreme low temperature conditions or in desublimation processes, and its potential application to decarbonise the marine transport is significant to avoid costs if using new infrastructure for ammonia or hydrogen manufacture. Our results indicate that ECT has potential to be a novel technique for monitoring dynamic CO2 frost formation during cryogenic carbon capture. The associated report is included in the data too. Accompanying paper: Preliminary study of CO2 frost formation during cryogenic carbon capture using tomography analysis - ScienceDirect, https://doi.org/10.1016/j.fuel.2022.125271.