The Trans-African HydroMeteorological Observatory (TAHMO) aims to develop a vast network of weather stations across Africa. Current and historic weather data is important for agricultural, climate monitoring, and many hydro-meteorological applications.

Watch the video below to learn more about our project.


The idea behind this project is to develop a dense network of hydro-meteorological monitoring stations in sub-Saharan Africa – one every 30 km. This entails the installation of 20,000 stations across the continent. By applying innovative sensor technology and ICT, TAHMO stations are both inexpensive and robust. Stations are placed at schools and integrated in educational programs, adding richness to the curriculum and helping foster a new generation of scientists. Local weather data will be combined with models and satellite observations to obtain insight into the distribution of water and energy stocks and fluxes.

Within this project, we have built a prototype of an acoustic disdrometer (rain gauge) that can be produced for €10, less than one percent of the cost of a commercial equivalent with the same specifications. The disdrometer was developed in The Netherlands and tested in Tanzania for a total project cost of €5000.

Listen to the rainfall recording from Tanzania [link].


Monitoring Africa’s environment is an important challenge if the continent’s resources are to be used in an optimal and sustainable manner. Food production and harvest predictions profit from improved understanding of water availability over space and time. Presently, African observation networks are very limited, and national governments and regional planners do not have the data to make proper decisions regarding investments in water resources infrastructure.


The ability to access historical climate data is critical in order to efficiently manage water resources. The limited number of weather stations in Africa is spread out over enormous distances; most are found in northern and southern Africa, leaving huge data gaps in the central part of the continent. Additionally, those African climate data which are currently available are not arranged in a convenient way for users to access; data sets are often incomplete and restricted to the public. There is often a lack of communication within countries and regions, creating data gaps at multiple levels. Another key challenge for climate monitoring in Africa is the availability of historical data; most collected data have been recorded on paper, and not cataloged electronically. With these data literally sitting forgotten on shelves in offices around the continent, they are at great risk of being lost forever. Accurate climate data are essential for agriculture, weather prediction and climate modeling. With an increase in quantity and quality of climate stations, along with the incorporation of historical data, we can move forward towards the goal of obtaining accurate climate data.


The TAHMO project is committed to serving the public by advancing the free and open exchange of hydro-meteorological data collected with its monitoring stations. By allowing the free download of all raw TAHMO data for scientific research and governmental applications, the project supports World Meteorological Organization (WMO) Resolution 40 and Resolution 25. Commercial applications of TAHMO data are considered on a case-by-case basis.

WMO Resolution 40 on the facilitation and co-operation of observing networks and the exchange of meteorological information is of interest to the international community, governments, and researchers alike. It states, “As a fundamental principle of the World Meteorological Organization (WMO), and in consonance with the expanding requirements for its scientific and technical expertise, WMO commits itself to broadening and enhancing the free and unrestricted international exchange of meteorological and related data and products.”

Similarly, the TAHMO project supports WMO Resolution 25, which “adopts a stand of committing to broadening and enhancing, whenever possible, the free and unrestricted international exchange of hydrological data and products, in consonance with the requirements for WMO’s scientific and technical programmes.” Allowing for free access to TAHMO monitoring data serves the public by beginning to close the existing hydro-meteorological data gaps in Africa and increasing the communication and application of this important information.