Seven long-term observation sites have been established in six regions across Austria, covering major ecosystem types such as forests, grasslands, and wetlands across a wide bioclimatic range. The purpose of these observations is to measure key ecosystem parameters serving as baselines for assessing the impacts of extreme climate events on the carbon cycle. The datasets collected include meteorological variables, soil microclimate, CO2 fluxes, and tree stem growth, all recorded at high temporal resolution (15–60 min) between 2019 and 2021 (including 1 year of average climate conditions and 2 comparatively dry years). The DOIs of the dataset can be found in the “Data availability” section. The sites will be integrated into the European Research Infrastructure for Integrated European Long-Term Ecosystem, Critical Zone, and Socio-Ecological Research (eLTER RI). Subsequently, new data covering the variables presented here will be continuously available through the data integration portal. This step will allow the data to reach their full potential for research on drought-related ecosystem carbon cycling.