Some temperature and CO2 measures have been made for one year in the cave of Ramioul and in the cave of Comblain-au-Pont, and for six months in the underground quarry of Petit-Lanaye inférieure. Temperature has been measured by dataloggers. These measures and the comparison between the different caves contributed to a better understanding of their climates. In the cave of Ramioul, closed by non insulated doors, the air movements are relatively low but there are some heat exchanges between the outside and inside air by conduction through the doors. The cave can be divided into two parts each with a different climatic behaviour. High and dangerous CO2 rates have already been measured in this cave. Rates fluctuate in an irregular way and without any connection with the natural seasonal cycle, and the CO2 origins stay uncertain. The cave of Comblain-au-Pont can be divided into two major parts: one enclosed and the other ventilated. The ventilated region is a “wind tube” during the winter, but it doesn’t reverse in the summer. On a larger scale, this region can be considered as a cold air trap despite its two exits, since it has a descendant morphology. In the underground carry of Petit-Lanaye inférieure, the low number of data doesn’t allow a complete diagnosis of the climate organisation, but can give a first idea for the summer period. We can already distinguish some parts that are more or less influenced by the outside temperature fluctuations, probably in relation with some air movements which organised themselves in a complex way in the labyrinthic galleries network. ; Des mesures de température et de CO2 ont été réalisées pendant un an dans la grotte de Ramioul et dans la grotte et abîme de Comblain-au-Pont, et pendant sixmois dans la carrière souterraine de Petit-Lanaye inférieure. La température a été mesurée de manière continue à l’aide de dataloggers. Ces mesures et la comparaison entre les différentes cavités ont permis de mieux comprendre le fonctionnement de leurs climats. Dans la grotte de Ramioul, qui ...