Standardized Precipitation Index: A precipitation anomaly is considered relativ to the mean precipitation of a reference period (1981-2010) and based on the underlying statistical distribution (Gamma). The anomlies are considered over different months (3, 6, 9, 12). (More information under: https://climate-indices.readthedocs.io/en/latest/)
Climate Modell Data
part of the calculation with python package: https://github.com/monocongo/climate_indices
More information about the climate model data source and methods can be found in the text files of the head data set (DOI: 10.58160/gGzexcbDikobkyvK, see "IsPartOf-DOI").