“We provide a weather report for the soil”

Andreas Brömser is an agri­cul­tural mete­o­rol­o­gist at the German Weather Service (DWD). He assists farmers in making forward-looking deci­sions with the help of soil mois­ture fore­casts.

August 2025

Text: Annina Werths
Photos: DWD-ZAMF, Dr. Christina Koppe / DWD

Mr Brömser, everyone is familiar with the weather fore­cast. But what is a soil mois­ture fore­cast?

It is an exten­sion of the tradi­tional weather fore­cast that we at the German Weather Service have specially devel­oped for agri­cul­ture. While weather fore­casts primarily include temper­a­ture, precip­i­ta­tion, and wind, a soil mois­ture fore­cast focuses on the amount of water currently in the soil and how this value is expected to change in the coming days and weeks. It is based on data regarding soil compo­si­tion, precip­i­ta­tion, and evap­o­ra­tion.

How do farmers benefit from being able to predict soil mois­ture?

Farmers can assess whether the soil will be drier or wetter than usual. The fore­cast provides an indi­ca­tion of when dry periods or over­sat­u­ra­tion are to be expected.

When it comes to seasonal esti­mates over several months, the fore­cast should be consid­ered more as a trend.

Andreas Brömser

How is it possible to look into the future of the soil?

By combining data from measure­ment stations and model calcu­la­tions. The German Weather Service oper­ates a network of 20 measure­ment stations in Germany that contin­u­ously provide data on mois­ture at various soil depths. At these stations, probes are buried at depths ranging from 10 to 90cm. They record the water content. These measure­ments are used to cali­brate a soil mois­ture model that calcu­lates values for the entire federal terri­tory. The model incor­po­rates further data like precip­i­ta­tion, temper­a­tures, and evap­o­ra­tion rates, over 70 different soil types, and several agri­cul­tural crops or forest tree species. The calcu­la­tion is performed on a 1x1km grid, allowing us to derive a daily updated simu­lated soil mois­ture condi­tion for each point in Germany.

The instal­la­tion of a casing for two lysime­ters and an access shaft for measuring soil mois­ture. This is a weigh­able, vege­tated cylinder filled with soil. The results from the lysimeter and the root scanner are incor­po­rated into the model for calcu­lating soil mois­ture.

Can farmers specif­i­cally check the condi­tion of their own soil?

Yes, this is possible via the soil mois­ture viewer on our DWD website. It is publicly acces­sible and suit­able for analysing the current soil mois­ture situ­a­tion, displaying the devel­op­ment over recent months, and esti­mating trends in dry or wet periods in the coming weeks. Each month, we receive up to 20,000 visits to the soil mois­ture viewer.

The view of the lysimeter from the access shaft. The cylinder houses the soil mois­ture sensors and three access points for the insertable root imaging scanner. This moni­tors root growth in the rele­vant soil layer. The results from the lysimeter and the root scanner contribute to the devel­op­ment of the model for calcu­lating soil mois­ture.
How the installed lysimeter looks from the soil surface. The amount of evap­o­ra­tion is calcu­lated by contin­u­ously measuring the weight and the seepage water escaping from below.

How reli­able are the soil mois­ture fore­casts?

The fore­casts are a useful guide, partic­u­larly regarding current soil condi­tions. The further you look into the future, the more uncer­tain it becomes. Espe­cially when it comes to seasonal esti­mates over several months, the fore­cast should be consid­ered more as a trend. Since actual soil condi­tions can vary on a small scale depending on the loca­tion, it is advis­able to combine personal obser­va­tions with the analysis and fore­cast data.”

What does the future hold for soil mois­ture measure­ment?

New sensor tech­nolo­gies will soon be able to measure not just at specific points, but over a broader area — within a radius of 20 to 50m. This allows for an even more precise assess­ment of the soil condi­tion, thus making it possible to feed more accu­rate initial data into the soil mois­ture model. The use of arti­fi­cial intel­li­gence will also play a role in future. It could help to further enhance the models and make fore­casts even more precise. For farmers, this means that those who become familiar with the tools today are well prepared for the demands of tomorrow.

How farmers in Germany can check their soil

The freely acces­sible “Soil Mois­ture Viewer” of the German Weather Service (DWD)

  • Access: This tool is publicly avail­able on the DWD website.
  • Func­tion: Farmers can view a graph­ical repre­sen­ta­tion of the current soil mois­ture in Germany here. The map shows colour-coded devi­a­tions from the normal value and provides a review of the soil mois­ture devel­op­ment over the past 12 months.
  • Farmers can obtain an initial assess­ment for their region.

Infor­ma­tion about Great Britain

Similar prod­ucts are likely being devel­oped in the UK. We are familiar with the “UK Water Resources Portal“, which provides daily obser­va­tion data on soil mois­ture. However, the portal does not currently offer a fore­cast.

Infor­ma­tion about Andreas Brömser

Andreas Brömser is a mete­o­rol­o­gist and has been with the German Weather Service (DWD) since 2017. He works in agrom­e­te­o­ro­log­ical consulting at Offen­bach, where he prepares weather fore­casts for farmers, analyses regional agri­cul­tural devel­op­ments, and creates agri­cul­tural content for the “ISABEL” agrom­e­te­o­ro­log­ical portal. In addi­tion, he works on monthly and weekly reviews as well as media enquiries concerning extreme weather events, such as drought or heavy rain­fall, and delivers presen­ta­tions at specialist agri­cul­tural confer­ences.