At the end of one-month-long period of very low outside temperatures (January 2017), air temperature was measured at 74 sites in 25 km long Postojna-Planina Cave System. Spatial data were further interpolated in GIS Surfer (Golden Software) to 10×10 m grid. Results show strong impact of ventilation that reduces average temperature of the karst massif (8.7-11.4 °C) to nearly freezing temperature close to the entrance. Additionally, strong impact is recognized by allogenic underground river that reduces air temperature of the middle part of cave system to about 4 °C. On the other hand, weakly ventilated passages indicate very stagnat temperature with les than 0.1 °C of annual variation. This study shows very varied conditions for underground fauna despite general belief that annual air temperature in caves is very constant. Measurements will be repeated at the end of summer when the highest temperatures are expected to calculate maximal annual temperature variation.

Cave microclimate is prone to important changes in certain passages due to intensive tourism. Monitoring the climatic parameters (air temperature, CO2) in Postojna-Planina Cave System helps to have a proper picture of the impact of tourism for the cave. It is very useful to compare if additional increase of temperature is associated with the changes at the surface climate. The dataset comprises two types of daily mean air temperature data: 1) the daily mean air temperature data (°C) measured in “Lepe jame” cave passage from Postojna Cave, counting constantly a very high number of tourists; the measurements were made in the same point, by three sensors placed at three different height points (in the wall cracks [T1], at ceiling level [T3], and at 2 m height [T2]). Values are recorded at 10 min intervals and then averaged for daily data (the dataset for Lepe jame cave passage is provided by MEIS Environmental consulting d.o.o. (http://www.meis.si/) while the data are part of the project "Assesment of natural and antropogenic processes in micrometeorology of Postojna cave system by numerical models and modern methods of data aquisition and transfer" [https://izrk.zrc-sazu.si/en/programi-in-projekti/assesment-of-natural-and-antropogenic-processes-in-micrometeorology-of-postojna#v]; 2) the surface daily mean air temperature measured at 2 m height (°C) at the Postojna meteorological station, as part of the national network of meteorological stations within the Environmental Agency of the Republic of Slovenia (ARSO; http://meteo.arso.gov.si/).

Data of type hydrology-hydrogeology measured on Le Toulourenc basin within the framework of the FONTAINE DE VAUCLUSE observatory, that is part of the KARST observatory network. The KARST observatory network aims to strengthen knowledge-sharing and to promote cross-disciplinary research on karst systems, in the framework of the OZCAR Critical Zone network Research Infrastructure. Data consist in 1 time series on 1 station(s). The measured parameters are: Discharge (m3/s). Measurements start on 07-06-1991 and end on 19-11-1992

Data of type hydrology-hydrogeology measured on Port-Miou basin within the framework of the PORT-MIOU observatory, that is part of the KARST observatory network. The KARST observatory network aims to strengthen knowledge-sharing and to promote cross-disciplinary research on karst systems, in the framework of the OZCAR Critical Zone network Research Infrastructure. Data consist in 3 time series on 1 station(s). The measured parameters are: Discharge (m3/s), Water level (cm). Measurements start on 16-12-2010 and end on 17-05-2022

Data of type hydrology-hydrogeology measured on Fontaine de Nimes basin within the framework of the FONTAINE DE NIMES observatory, that is part of the KARST observatory network. The KARST observatory network aims to strengthen knowledge-sharing and to promote cross-disciplinary research on karst systems, in the framework of the OZCAR Critical Zone network Research Infrastructure. Data consist in 1 time series on 1 station(s). The measured parameters are: Discharge (m3/s). Measurements start on 28-10-1998 and end on 05-07-2021

Data of type hydrology-hydrogeology measured on Etang de Thau et Vic basin within the framework of the MEDYCYSS observatory, that is part of the KARST observatory network. The KARST observatory network aims to strengthen knowledge-sharing and to promote cross-disciplinary research on karst systems, in the framework of the OZCAR Critical Zone network Research Infrastructure. Data consist in 1 time series on 1 station(s). The measured parameters are: Discharge (m3/s). Measurements start on 14-10-2002 and end on 28-11-2005

Data of type climatology-meteorology-atmosphere measured on Port-Miou basin within the framework of the PORT-MIOU observatory, that is part of the KARST observatory network. The KARST observatory network aims to strengthen knowledge-sharing and to promote cross-disciplinary research on karst systems, in the framework of the OZCAR Critical Zone network Research Infrastructure. Data consist in 2 time series on 1 station(s). The measured parameters are: Atmospheric pressure (cm). Measurements start on 22-09-2014 and end on 18-05-2022

Data of type hydrology-hydrogeology measured on L'Isle basin within the framework of the KARSTS AQUITAINS observatory, that is part of the KARST observatory network. The KARST observatory network aims to strengthen knowledge-sharing and to promote cross-disciplinary research on karst systems, in the framework of the OZCAR Critical Zone network Research Infrastructure. Data consist in 1 time series on 1 station(s). The measured parameters are: Discharge (m3/s). Measurements start on 01-07-2005 and end on 02-08-2018

Data of type hydrology-hydrogeology measured on Dardennes - Le Las basin within the framework of the PORT-MIOU observatory, that is part of the KARST observatory network. The KARST observatory network aims to strengthen knowledge-sharing and to promote cross-disciplinary research on karst systems, in the framework of the OZCAR Critical Zone network Research Infrastructure. Data consist in 1 time series on 1 station(s). The measured parameters are: Water table elevation (m ASL). Measurements start on 19-10-2012 and end on 16-03-2019

Data of type bacteriology measured on Le Lez (Méditerranée) basin within the framework of the MEDYCYSS observatory, that is part of the KARST observatory network. The KARST observatory network aims to strengthen knowledge-sharing and to promote cross-disciplinary research on karst systems, in the framework of the OZCAR Critical Zone network Research Infrastructure. Data consist in 8 time series on 4 station(s). The measured parameters are: Escherichia coli (CFU/100 mL), Total coliform (CFU/100 mL). Measurements start on 21-10-2008 and end on 16-12-2018