This dataset contains the data collected during the SNSF BRIDGE GREENsPACK project (Grant no. 40B2-0_187223) in association with the recent publication entitled “Biodegradable materials as sensitive coatings for humidity sensing in S-band microwave frequencies”. This work aims to study the humidity response of eco-friendly materials in the S-band (2-4GHz) using a microstrip line resonating at 3.3GHz. Several sensors coated with different biodegradable materials were tested and simulations have been performed. The S12 signal of the resonator was measured when varying the humidity. The data that was collected in the frame of this work is present in this repository. More information about the content of the dataset is present in the included README file.