graph_weather is a research-oriented deep learning library for weather forecasting with graph neural networks. It implements multiple model families—GraphCast-inspired encoder/processor/decoder models, the diffusion-based GenCast and GenDA, the ensemble FGN, WeatherMesh, Aurora, FengWu-GHR, and CaFA—along with a substantial set of data loaders, loss functions, training scripts, and evaluation utilities. The package is structured as a Python library with HuggingFace Hub model integration, PyTorch Lightning training support, and a comprehensive test suite, giving it a hybrid character: it is fundamentally research code, but packaged and tested with application-grade discipline. Entry points include GraphWeatherForecaster, GraphWeatherAssimilator, WeatherStationReader, and various dataset classes, while training scripts live under train/.