CHELSA (Climatologies at High resolution for the Earth's Land Surface Areas) is one of the most widely used climate datasets in ecology, biogeography, and environmental modeling.
Developed at the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), it provides global temperature and precipitation climatologies derived from ERA reanalysis data with mechanistic downscaling that accounts for how terrain shapes local climate. This makes CHELSA a strong choice for any spatial analysis where topography matters — species distribution modeling in mountain ranges, agricultural suitability assessments in varied terrain, or climate risk mapping across regions with complex elevation gradients.
CHELSA's 19 bioclimatic variables are a standard input for habitat and ecological niche models, and the availability of matching CMIP6 projections means you can run the same models against future climate scenarios without switching datasets or resolution.
All layers are distributed as GeoTIFFs, so they load directly into any raster-capable GIS platform, including Atlas. For researchers and analysts working at landscape to continental scales, CHELSA provides a consistent, high-resolution climate baseline that pairs well with land cover, soil, and biodiversity layers.
