Global Hydrological Status and Outlook System (HydroSOS)

The Challenge

HydroSOS Flyer 2021Globally hydrological variability poses one of the greatest threats to the world's population. There are an increasing number of people at risk from water-related hazards and rapidly growing demands on water resources. However, there is currently no global system which is capable of assessing the current status of surface and groundwater systems or predicting how they will change in the immediate future.

HydroSOS aims to provide the crucial global scale information needed to help water users understand the current status of the world's freshwater systems and adapt to changes by harnessing new technologies and manage water resources with science-based information.

The System

This important initiative, envisioned in the Commission for Hydrology and now overseen by the WMO Hydrological Assembly, has been approved by WMO Congress (see Resolution 25 of Cg-18) and intends to provide an operational system capable of assessing the current hydrological status and its likely near-future outlook (sub-seasonal to seasonal time frames) for all areas of the globe.

Read more.

Message from the HydroSOS Task Team Leader

Please click here for a video about HydroSOS and the current progress achieved by the new initiative.

Summary of activities under HydroSOS (up to May 2023)

Presentation on country examples: Please click here.

Presentation on overview and standard products: Please click here.

Presentation on HydroSOS Regional Implementation Plans: Please click here.


Contact us

For any HydroSOS-related inquiries, please send an email to


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