Midas Open is the open data version of the Met Office Integrated Data Archive System (MIDAS) containing land surface station data starting from 1853 and ending at the of the previous complete year. This collection comprises of hourly and daily weather measurements and observations of parameters relating to temperature, rainfall, sunshine, radiation, wind and weather observations such as present weather codes, cloud cover, snow etc.

The collection contains land surface observations data from those stations where the data have been designated as public sector information. Prior to version v202407 this consisted of stations operated by the Met Office only, but from version v202407, daily and hourly rainfall observations from stations with gauges owned by the Environment Agency (EA), Scottish Environment Protection Agency (SEPA) and Natural Resources Wales (NRW) have also been included in the collection. All of these data are provided under an Open Government Licence. As such, with the v202407 release, the current collection contains the following proportions of the fuller MIDAS dataset collection:

96% of daily temperature observations
96% of daily weather observations
92% of hourly weather observations
58% of daily rainfall observations - see note below
94% of hourly rainfall observations
98% of soil temperature observations
96% of solar radiation observations
90% of mean wind observations

The lower proportion of UK daily rainfall network data available in the MIDAS Open collection is a consequence of excluded rain gauges being owned by third parties (e.g. private individuals or organisations) where inclusion of the data in the collection has not yet been agreed. Other data may be excluded at present due to their historical nature and resulting issues around establishing their provenance permitting their release.

The fuller "Met Office Integrated Data Archive System (MIDAS) Land and Marine Surface Stations Data (1853-current)" collection is made available for academic use via the Centre for Environmental Data Analysis.

The MIDAS Open collection is updated annually in a delayed mode to ensure that data acquisition and quality control procedures have all been completed. Quality controlled (qc-version-1) and non-quality controlled (qc-version-0) data are available from 1853 where available, although this will vary by station depending on the operation period of the station. The collection includes stations which are currently operational as well as stations which were operational in the past and have since closed.

Each version of the dataset will include data up until the end of the previous complete year relative to the year in the version number of the dataset (e.g. v202407 included data up until the end of 2023).

Note: This collection does not supersede the full MIDAS collection which is also archived at CEDA.