EU Open Data and Weather Archives
A Common Baseline for Meteorological Open Data
Historically, access to national meteorological archives varied widely across Europe. Some datasets were freely available, while others required payment, registration, negotiated access or restrictive licences, complicating cross-border analysis.
The regulation established a common European baseline while national meteorological services continued open-data initiatives that had begun on different timelines. The legal framework was defined by the European Open Data Directive (officially Directive (EU) 2019/1024 on open data and the re-use of public sector information) and, more specifically for publication obligations, the implementing regulation on High-Value Datasets (HVD) (Regulation (EU) 2023/138). Rather than being the sole cause of openness, the directive established a European legal floor that required public-sector datasets within scope to be made available free of charge, under an open license, in machine-readable formats, and via APIs and, where relevant, bulk download.
The implementing regulation is explicit in its baseline requirements for meteorological data. As outlined in the Annex, the meteorological high-value datasets include:
“observations data measured by weather stations, validated observations (climate data), weather alerts, radar data and numerical weather prediction (NWP) model data.”
By solidifying these requirements, the policy intervention established a common European legal baseline, complementing ongoing national initiatives.
Establishing a New Baseline: The National Trajectories
The directive complemented and formalized the efforts of national meteorological institutions across Europe. Here is how three agencies navigated the transition to open data, establishing the foundation for tools like the Climate Explorer.
1. Germany’s Deutscher Wetterdienst (DWD)
Germany’s National Meteorological Service, the Deutscher Wetterdienst (DWD), transitioned to an open-data model well before the 2019 EU Directive. Under an amendment to the German Federal Law on the Deutscher Wetterdienst (DWD-Gesetz) enacted on July 25, 2017, the DWD was legally mandated to provide the vast majority of its meteorological and climatological data free of charge. In this context, the subsequent European Directive did not force Germany’s hand; rather, the EU rules aligned with and reinforced the DWD’s established trajectory.
The DWD OpenData portal provides a comprehensive open meteorological repository. It provides access to standard hourly and daily climatological summaries, as well as high-resolution 10-minute meteorological measurements (documented in the DWD CDC Description).
This granular data, covering air temperature, precipitation, wind dynamics, and solar radiation, allows researchers to analyze short-duration weather phenomena that are not captured in daily averages. These datasets reduce data-access barriers for research and applications that require sub-daily meteorological observations, including climate analysis and renewable-energy modelling.
2. Météo-France
France’s approach to open data required a more significant internal transformation. Historically, Météo-France commercialized substantial portions of its high-resolution historical data. Driven by national open-data policies and reinforced by the European Open Data Directive, Météo-France’s transition to public access involved updating its technical data delivery systems.
Today, the Météo-France Open Data API (accessible via the Portail API Météo-France) provides free access to observation and climatological datasets. Its coverage across oceanic, continental, alpine, and Mediterranean climate zones supports analysis of weather and climate across metropolitan France and its overseas territories.
A key public dataset contains precipitation observations at six-minute temporal resolution, with records extending back as far as July 2005 for some stations (available on data.gouv.fr). Files are supplied by department and updated at intervals ranging from daily to annual, depending on their age. This temporal resolution can support retrospective analysis of short-duration precipitation events relevant to hydrology and urban drainage.
3. Poland’s IMGW-PIB
The Polish Institute of Meteorology and Water Management – National Research Institute (IMGW-PIB) provides a critical lens into the climate of Central and Eastern Europe.
The IMGW-PIB open data portal (accessible at danepubliczne.imgw.pl) reflects the broader European push toward transparency, bolstered by the directive’s legal framework. It provides access to historical measurement and observation records from Poland’s meteorological network. The available archive supports analysis of variables such as temperature, precipitation, wind and snow depth, although coverage varies by station, variable and period.
Through open data portals, users can access historical state records to study temperature patterns, such as the urban heat island effect in Warsaw, or track variables like snow depth in the Tatra mountains.
Interoperability: WIS 2.0 and MeteoGate
The ultimate goal of opening meteorological data is not just release, but interoperability. However, the Open Data Directive did not itself create a single European meteorological exchange standard.
That role belongs primarily to WIS 2.0, the World Meteorological Organization’s modern framework for making meteorological data discoverable and accessible through web-based services, notifications, and interoperable metadata. In Europe, EUMETNET’s Federated European Meteo-Hydrological Data Infrastructure (FEMDI) and the MeteoGate documentation outline how work aligns with WIS 2.0 principles. This helps national services make data easier to discover and access while supporting compliance with the WMO Unified Data Policy and the EU High-Value Dataset rules.
In practice, this matters because interoperable catalogues, APIs, and notification mechanisms reduce the amount of country-specific plumbing needed to work with near real-time observations. Rather than treating the directive as the origin of these standards, it is more accurate to say that its publication requirements are consistent with the wider move toward interoperable, web-based delivery.
This interoperability is showcased in the EuroMeteo Explorer, which leverages the MeteoGate platform to aggregate WIS 2.0-aligned observation feeds, providing a live, continent-wide view of Europe’s weather as it happens.
Why This Matters for Climate Resilience
The liberalization of meteorological data across Europe provides useful input for climate adaptation and resilience planning, although access alone does not guarantee particular societal outcomes.
- Democratic Access to Science: Independent researchers and journalists have the data access required to verify climate trends without relying solely on state-issued summary reports.
- Economic Potential: The availability of free historical baselines creates opportunities for startups and agricultural firms to build hyperspecialized weather risk models.
- Preparedness Planning: Access to high-resolution historical data enables civic engineers to plan infrastructure (like stormwater drains in Paris or wind turbine arrays in the North Sea) against observed extremes, rather than interpolated guesses.
The European open-data movement demonstrates that returning high-quality, state-funded meteorological observations to the public domain establishes the necessary conditions for the scientific and technological ecosystem to benefit. As tools like Climate Explorer continue to build bridges to these open APIs, the barrier between global weather archives and the people who need them is steadily diminishing.
Frequently Asked Questions (FAQ)
What is the European Open Data Directive?
The European Open Data Directive (Directive (EU) 2019/1024) is a legislative framework that establishes minimum rules for the re-use of public-sector information across the European Union. While it does not mandate that every public body publish all its data, it requires that specific categories of High-Value Datasets (such as meteorological, geospatial, and environmental data) be made available free of charge. The goal is to stimulate digital innovation, increase transparency, and break down paywalls on public-funded information.
Why are weather and climate datasets considered High-Value?
Under the implementing Regulation (EU) 2023/138, meteorological data is explicitly classified as a High-Value Dataset because its widespread availability provides socio-economic benefits. Free access can support climate research, agricultural planning, disaster-risk analysis and renewable-energy applications by reducing financial and technical barriers to obtaining data.
Is historical weather data now completely free in Europe?
No. The rules do not mean that every historical weather dataset in Europe is now free. What they do mean is that specific high-value meteorological datasets within scope must be made available free of charge, machine-readable, and via APIs and, where relevant, bulk download. In practice, this has opened core observation, climate, radar, warning, and forecast datasets from services such as Germany’s DWD, France’s Météo-France, and Poland’s IMGW-PIB, but coverage and implementation still vary by country and dataset.
Do I need special software to access this open meteorological data?
While much of the raw data is provided via APIs or bulk downloads (which often require some technical skill to query and parse), platforms like Climate Explorer were built specifically to bridge this gap. Climate Explorer connects directly to these official open data portals, allowing anyone with a web browser to visualize and export the data without writing a single line of code.
Data Annex
(No local computations were performed for this article.)
| National Agency | Key Implementation Legislation / Portal |
|---|---|
| DWD (Germany) | First Act Amending the DWD Act (July 2017) |
| Météo-France (France) | Portail API Météo-France |
| IMGW-PIB (Poland) | IMGW Open Data Portal (Dane Publiczne) |
| European Legislation | Description |
|---|---|
| Directive (EU) 2019/1024 | Open data and the re-use of public sector information |
| Regulation (EU) 2023/138 | Laying down a list of specific high-value datasets |
Data Sources
- Directive (EU) 2019/1024: EU Directive on open data and the re-use of public sector information.
- Regulation (EU) 2023/138: Implementing regulation on High-Value Datasets.
- DWD Open Data: DWD open data provisions.
- DWD Climate Data Center: DWD climate data portal.
- DWD Ten-Minute Air Temperature Documentation: Technical description of 10-minute records.
- Météo-France Portail API: Official API portal for Météo-France datasets.
- Météo-France 6-Minute Climatological Data: Base 6-minute observation records.
- IMGW-PIB Dane Publiczne: Official repository for Polish meteorological data.
- WMO WIS 2.0 Overview: World Meteorological Organization WIS 2.0 information.
- EUMETNET FEMDI: Federated European Meteo-Hydrological Data Infrastructure.
- MeteoGate Documentation: Documentation for the MeteoGate platform.