This platform was developed through a project funded by the Water Research Commission (WRC) titled “Development of a web-based hydrometeorological indices app to support decision-making for weather- and climate-sensitive agricultural activities in South Africa”
The agricultural sector is highly sensitive to weather- and climate-related risks. Crop and livestock production can be significantly affected by the timing and intensity of rainfall, the frequency of very hot days, and the availability of water in the landscape. As such, the sector would greatly benefit from easy access to reliable, up-to-date information to support both short-term and seasonal planning and decision-making.
For short-term decisions, farmers need timely weather insights, such as rainfall over the past 10 days, to evaluate recent conditions and anticipate near-term risks. Likewise, supporting information on water availability, including surface water availability indices, can guide actions related to irrigation, grazing, and water resource use. Yet, such information is not always readily available to agricultural stakeholders in South Africa. It typically requires a high level of technical skill to extract from raw datasets and is not consistently operationalised or accessible in formats suited to end users.
This project addresses that gap through the development of a web-based hydrometeorological indices app, known as the Weather Risk site. The app delivers weather and water availability information in the form of targeted indices tailored to agricultural needs. These indices are designed to simplify complex datasets and provide meaningful insights to help farmers and agricultural advisors manage weather-related risks.
As part of the initiative, we conducted a review of existing weather, climate, and water information tools and identified indices most relevant to agricultural decision-making in the South African context. The resulting app provides a range of short-term historical and, where feasible, forecast indices related to weather risk and water availability. The interface is intentionally user-friendly, designed to support early warning, guide short-term monitoring, and enable timely, responsive decisions in the face of changing conditions.
Ultimately, the app serves as a national-scale resource to help agricultural users evaluate weather-related risks and distinguish between favourable and adverse conditions for farming across South Africa.
The Weather Risk app is a freely accessible web-based tool designed to deliver weather and water availability indices relevant to agriculture across South Africa. It integrates near–real-time observational data, short-term forecasts, and key water indicators to support informed decision-making at daily to weekly timescales. Although the primary platform is free to use, future developments may include optional paid products.
The app can be accessed via www.weatherrisk.arc.agric.za/
All supporting information and documentation are available via the App_user_guide
As part of this project, we are continously engaging with stakeholders to better understand their needs, preferences, and challenges related to weather and climate information. These engagements are informing the development and refinement of the hydrometeorological indices app and other project outputs.
- We request that users of the app fill out a stakeholder needs and constraints questionnaire:
This questionnaire is designed to help the ARC Agrometeorology Division understand how stakeholders currently use weather and climate information, which formats and indices are most useful, and what constraints they face in accessing or applying this information. In turn it can help us strengthen the weather and climate services we offer. Please contribute to answering this questionnaire, accesible via: https://forms.gle/vume1JRK3DG77RP67
- We also request that users of the Weather Risk App complete a user feedback questionnaire:
This evaluation form collects feedback on the usability, functionality, and relevance of the hydrometeorological indices app to guide future improvements. Please contribute to answering this questionnaire, accessible via: https://forms.gle/z2aSdZhHvhPqwRHh7
This project has produced several research and outreach outputs that contribute to the advancement of weather- and climate-related decision-support for the agricultural sector in South Africa. These outputs are available under the Publications folder and include the following:
-Roffe, S. (2024) Climate indices for informed agricultural decision-making, Stockfarm. Available online: https://agriorbit.com/climate-indices-for-informed-agricultural-decision-making/
-Roffe, S. and Singo, M. (2024) Evaluation of ERA5-based reanalysis products for the representation of cold temperature indices over southern Africa, Society of South African Geographers Biennial Conference Proceedings. Available online: https://www.ssag.co.za/wp-content/uploads/2024/11/SSAG_2024_Proceedings.pdf
-Myeni, L. and Roffe, S. (2025) Towards effective weather and climate services in South Africa: profiling sectoral needs and constraints. Environmental Development, 55: 101240. Available online: https://doi.org/10.1016/j.envdev.2025.101240
-Roffe, S. (2025) Shaping South Africa's weather and climate services - together for agriculture. AgriAbout. Available online: https://heyzine.com/flip-book/0d675fc05b.html
In addition, selected scripts used to calculate the weather indices featured in the app are openly shared under the Hydromet_indices folder. These resources support transparency, reproducibility, and broader use of the indices in research, operational contexts, and policy support.
This is a multi-institutional project funded by the Water Research Commission (Project no. C2023/2024-01182).
The forthcoming Weather Risk App is being developed by researchers from the Agrometeorology and Water Science Divisions, along with software developers at the Agricultural Research Council (ARC), in collaboration with other partners. Special thanks go to Mr Philip Beukes, who served as the lead developer and played a central role in the design, implementation, and overall functionality of the platform. His contribution has been instrumental to the success of this tool. Mr Gert de Nysschen also supported the app development.
Dr Sarah Roffe led the scientific coordination of the app, with Dr Johan Malherbe, Dr Michael van der Laan, and Dr Cindy Viviers contributing significantly to the identification and integration of the weather and water indices presented in the app. Dr Ramontsheng Rapolaki contributed to the conception of the app idea, while stakeholder engagement work with Dr Lindumusa Myeni supported the selection and time scales of the weather indices included.
In addition to the app development, the project has supported a range of research activities led by Dr Sarah Roffe. Researchers contributing to this work through scientific input and/or postgraduate student supervision include Dr Michael van der Laan (ARC), Dr Johan Malherbe (ARC), Dr Teboho Masupha (ARC), Dr Lindumusa Myeni (North-West University), Dr Adriaan van der Walt (University of the Free State), Dr Cindy Viviers (formerly ARC), Dr Ramontsheng Rapolaki (South African Weather Service), Dr Mokhele Moeletsi (ARC), and Mr Mukovhe Singo (ARC), who is involved as an intern researcher. Postgraduate students working on research outputs linked to the project include Ms Namhla Mkiva, a PhD student affiliated with North-West University, as well as MSc students Ms Dimakatso Ndaleni, Mr Ngwako Mohale, Ms Nicolle Loader, and Mr Munei Mugeri, all affiliated with ARC and/or the University of the Free State.
In addition to the development of the app, the project has produced several research outputs, with some work already complete and others ongoing. These contributions reflect the collaborative, cross-institutional nature of the initiative and its broader goal of supporting agriculture through weather-informed decision-making tools.
Feel free to email Sarah Roffe (RoffeS@arc.agric.za) if you have any comments, requests or questions.
