Abstract Very deep coal seams which are unlikely to be mined may be considered for CO 2 sequestration. The main objective of this study is to investigate the effect of temperature on the permeability of naturally fractured coal. Permeability tests were conducted on naturally fractured bituminous coal samples using high pressure triaxial equipment for five different injecting pressures (8–13 MPa) under two different confinements (20 and 24 MPa) and five different temperatures (25–70 °C). The experimental data were then used to develop an appropriate numerical model using the COMET 3 simulator to model the temperature effect on permeability at temperatures up to 200 °C. According to the measured permeability values and the developed lab-scale model, there is a clear increase in CO 2 permeability with increasing temperature for any confining pressure at high injecting pressures (more then 10 MPa). However, for low injecting pressures (less than 9 MPa) temperature effect is not so much. With increasing injecting pressure, CO 2 permeability decreases at low temperatures (less than around 40 °C), and increases at high temperatures (more than 50 °C). Interestingly, the temperature effect on permeability is significant only up to around 90 °C condition within the 25–200 °C temperature limit. These observations are related with the sorption behavior of the adsorbing CO 2 during the injection. However, there is no noticeable temperature effect on N 2 permeability as it does not create any swelling effect in coal matrix.