This dataset contains the machine learning training data files, pretrained model weights and results for the paper Exploiting radar polarimetry for nowcasting thunderstorm hazards using deep learning, submitted to Natural Hazards and Earth System Sciences, 2023. The radar dataset can be found at the following Zenodo repository: https://doi.org/10.5281/zenodo.6325370 For instructions for using the data, please see the GitHub code repository at https://github.com/meteoswiss/c4dl-polar. Download all the files here and extract the contents to the following subdirectories in the ML code directory: Training data (patches_quality-index_2020.zip or patches_*_2020.nc) -> data/2020/ Results: (results.zip) -> runs/run*/results/ Pretrained models (models_run*) -> runs/run*/