The climate data (climateData) API service contains quality controlled meteorological observation data from Denmark (DNK) and Greenland (GRL). You can read more about climate data and how they are attained under data information.
If you want to download large quantities of historical climate data, we recommend that you use DMI’s bulk download service. The service lets you download .zip files, each containing historic data for a month going back to 2011 for Denmark and 2014 for Greenland. You can also download all historic data by selecting the file all.zip.