Since DMI was established in 1872, the institute has been responsible for measuring and recording meteorological observations from a wide range of observation stations across the Danish Realm. 
Over the years, these data have been published in a number of publications, including meteorological yearbooks containing daily observations of meteorological parameters such as temperature, precipitation, humidity, wind speed, cloud cover, and air pressure. 

This dataset with historical observations covers a time period of 1867-1983.
The daily observations have an almost constant format in all yearbooks throughout the time period.
There are only minor variations, mainly consisting of some parameters being discontinued while others were introduced. Minor variations of changes in observations of weather types might occur as well.

For further details read here: www.dmi.dk/publikationer 

Meteorological Yearbook Digitalization

The digitalization of DMI’s daily observations was carried out using an advanced multi-model AI pipeline, developed in collaboration with an external provider. The process transforms analogue image files into structured data.

Data availability

The historical observations are available here: https://download.dmi.dk/public/opendata/ 

Please note that the Meteorological Yearbook was not published in the years 1971–1975, 1977, and 1978.

Quality control

Over the years, the data have been subject to quality control prior to publication. A certain level of quality control has been carried out on the tabulated data, aimed at identifying unrealistic values and parameters that are internally inconsistent.

DMI is working on developing a model that automatically performs post-validation of the tabulated daily values by comparing them with the original monthly means and carries out a climatological quality control.
For the time being, the data should therefore be treated with caution due to the possibility of errors.