The Intensity-Duration-Frequency (IDF) product, developed by the Ghana Meteorological Agency (GMet), is a critical tool for supporting climate-resilient infrastructure planning and flood risk management across Ghana. IDF curves illustrate the statistical relationship between rainfall intensity, event duration, and the frequency (or return period) with which such events are likely to occur.

The product is based on high-quality historical rainfall data collected through GMet’s nationwide network of both manual and automatic weather stations. These data are processed using robust statistical techniques to ensure accuracy and reliability. The resulting IDF curves provide essential input for:

• Designing effective stormwater drainage systems
• Developing flood control and protection infrastructure
• Planning urban and rural development in flood-prone areas
• Supporting climate adaptation strategies and early warning systems

As rainfall extremes become more frequent and intense due to climate change, the relevance and importance of the IDF product continue to grow. To reflect Ghana’s spatial rainfall variability, GMet has customized its IDF datasets for different agro-ecological zones, urban areas, and hydrological basins.

The IDF product is made available as downloadable charts and tables, accompanied by detailed technical documentation to guide users in its application. For specific data requests or tailored support, users are encouraged to contact GMet Client Services for further engagement