Repowise scores google-research/arco-era5 at 9.2 out of 10 for code health, which reads as excellent, alongside maintainability 9.0 and static performance 9.8 on the same scale. There are 47 open findings across the three pillars, and the lowest-scoring file is resize_zarr.py at 7.1. Scores are computed from complexity, duplication, churn and git fix history, not from a linter.