Explore how weather data changes over time

Climate and climate change are among the topics whose long-term importance has been known for many years. At the same time, there is often an impression that necessary changes are progressing only slowly and that long-term developments take a back seat to short-term interests.

A factual look at the available observations can help make developments over longer periods easier to understand. Large quantities of historical weather and climate data are available. However, they are distributed across different meteorological services, public authorities and data portals, and stored in different files and formats. This often makes it time-consuming to find suitable time series, place them in context and compare them.

Climate Chronicle therefore brings this data together in a consistent, easy-to-read view. Maps, timelines and charts are intended to provide an accessible way to explore the observations, both for interested non-specialists and for other people and groups who use or want to examine historical weather and climate data more closely.

The focus is on the available data and its transparent statistical processing. The basis is formed by measurements from specific weather stations. Climate Chronicle therefore shows the development at individual measurement sites, not an area-wide estimate for every region.

A number of clear principles determine how Climate Chronicle selects, processes and displays measurement data.

A great deal of work takes place before a map or chart becomes visible. The data comes from different countries and meteorological services. File formats, dates, labels, units and available periods often differ.

Climate Chronicle brings these differences into a common structure. Stations, months and metrics can therefore be loaded, displayed and compared reliably.

During processing, suitable data fields are assigned and number formats are standardised. Missing values are not filled in. Calculated views are identified separately; station observations are not turned into area-wide measurement series.

I try to keep the data for all available countries up to date on a regular basis. This does not happen every day; I update it when I have the time and motivation.

With new data releases, there is more involved than simply adopting the values: data for each country has to be prepared, checked and incorporated into the respective metrics first. That is why the latest readings may not always appear on the site immediately.

If a data set is a little behind, this does not mean that anything is broken; the next update will follow as soon as I get to it.

Climate Chronicle has a modular technical foundation. Data that can be transferred to the shared format can therefore be integrated into the existing structure with manageable effort.

Existing small helper tools can convert different data into the format required by the website. Further external data can be integrated in the same way if it is suitable for the shared structure. This makes it possible to add further data collections and new topics in the future and can help place weather and climate developments in context from different perspectives.

Suggestions for further data or topics are welcome. If suitable data is available, integration into Climate Chronicle can be considered.