CHELSA (Climatologies at high resolution for the earth’s land surface areas) is a very high resolution (30 arc sec, ~1km) global downscaled climate data set currently hosted by the Swiss Federal Institute for Forest, Snow and Landscape Research WSL. It is built to provide free access to high resolution climate data for research and application, and is constantly updated and refined.

It includes climate layers for various time periods and variables, ranging from the Last Glacial Maximum, to the present, to several future scenarios.

CHELSA is based on a mechanistical statistical downscaling of global reanalysis data or global circulation model output and is freely available in the download section.