SuRT-GeoHarmonizer is an open R and Python command-line workflow for converting heterogeneous environmental rasters into consistent, provenance-labelled administrative-unit GeoJSON layers. It provides a provider-agnostic raster and polygon interface, Rwanda reference builders for CHIRPS rainfall, ERA5-Land temperature, MODIS NDVI, and HAND terrain, fail-closed evidence classification, positive and negative tests, independent release-contract validation, and versioned integrity records. The software produces descriptive environmental summaries and does not claim validated hazards, forecasts, epidemiological effects, or operational recommendations. If you use SuRT-GeoHarmonizer, cite the software release identified below.