East Africa - CHIRPS Seasonal Rainfall Accumulation Anomaly by Pentad

Seasonal rainfall accumulation anomaly for East Africa derived from CHIRPS data, showing deviation from the 1981-2010 historical average in millimetres. Use this layer for drought early warning, seasonal forecast validation, agricultural planning, and humanitarian response in the Horn of Africa.

Rainfall anomaly refers to the difference between the observed rainfall and the long-term average for a specific location and time period. It indicates whether rainfall conditions are above or below normal. Positive anomalies represent higher-than-average rainfall, while negative anomalies indicate below-average rainfall. These anomalies are essential for monitoring climate variability, including droughts and floods, and for assessing their impacts on agriculture, water resources, and other sectors. For this analysis, CHIRPS daily rainfall data for Ethiopia were utilized, covering the month of March 2024, 2025 and 2025. Rainfall anomalies for month of March were calculated by subtracting the long-term average (2000–2020) from the observed rainfall values for the same period.

Precipitation data is delivered on a daily basis. The source of this dataset is CHIRPS (Climate Hazards Group InfraRed Precipitation with Station) quasi-global rainfall dataset, starting from 1981 up to near present. The value of each pixel represents the total of daily precipitation in the month expressed in mm (1mm=1l/m² or 1mm=10m³/ha). The data is provided from January 2009 to 2024. **Data publication:** 2020-01-01 **Supplemental Information:** No data value: -9999 Unit: mm (1mm=1l/m² or 1mm=10m³/ha) Map code : L1-PCP-M Scale Factor : 0.1 Conversion factor: the pixel value in the downloaded data must be multiplied by 0.1 New dekadal data layers are released approximately 5 days after the end of a dekad. A higher quality version of the same data layer is uploaded after 6 dekads have passed. This final version of the dekadal dataset has a higher quality because gap filling and interpolation processes, where needed, have been based on more data observations. This implies that other temporal aggregations (monthly, seasonal, annual), and layers that depend on those, are updated as well. Practically this means that a final annual aggregation of the most recent full calendar year can only be produced after the end of February. Likewise, the final monthly aggregation of the most recent calendar months can only be produced 2 full months later. **Citation:** FAO 2018. WaPOR Database Methodology: Level 1. Remote Sensing for Water Productivity Technical Report: Methodology Series. Rome, FAO. 72 pages. Licence: CC BY 4.0 IGO **Contact points:** Metadata Contact: [WaPOR](mailto:wapor@fao.org) Resource Contact: [WaPOR](mailto:wapor@fao.org) **Data lineage:** See daily Precipitation (L1_PCP_E) for further information. The monthly data is obtained by taking the daily PCP, summing the days of each month. **Resource constraints:** Creative Commons Attribution 4.0 International (CC BY 4.0) **Online resources:** Download the data from Google Cloud Storage

Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) is a quasi-global rainfall dataset spanning 50S to 50N from 1981 to near present. It blends 0.05 degree satellite imagery with in-situ station data to create gridded rainfall time series for trend analysis and seasonal drought monitoring.

Precipitation data is delivered on a daily basis. The source of this dataset is CHIRPS (Climate Hazards Group InfraRed Precipitation with Station) quasi-global rainfall dataset, starting from 1981 up to near present. The value of each pixel represents the total of daily precipitation in the year expressed in mm (1mm=1l/m² or 1mm=10m³/ha). The data is provided from January 2009 to 2022. **Data publication:** 2020-01-01 **Supplemental Information:** No data value: -9999 Unit: mm (1mm=1l/m² or 1mm=10m³/ha) Map code : L1-PCP-A Scale Factor : 0.1 Conversion factor: the pixel value in the downloaded data must be multiplied by 0.1 New dekadal data layers are released approximately 5 days after the end of a dekad. A higher quality version of the same data layer is uploaded after 6 dekads have passed. This final version of the dekadal dataset has a higher quality because gap filling and interpolation processes, where needed, have been based on more data observations. This implies that other temporal aggregations (monthly, seasonal, annual), and layers that depend on those, are updated as well. Practically this means that a final annual aggregation of the most recent full calendar year can only be produced after the end of February. Likewise, the final monthly aggregation of the most recent calendar months can only be produced 2 full months later. **Citation:** FAO 2018. WaPOR Database Methodology: Level 1. Remote Sensing for Water Productivity Technical Report: Methodology Series. Rome, FAO. 72 pages. Licence: CC BY 4.0 IGO **Contact points:** Metadata Contact: [WaPOR](mailto:wapor@fao.org) Resource Contact: [WaPOR](mailto:wapor@fao.org) **Data lineage:** See daily Precipitation (L1_PCP_E) for further information. The annual data is obtained by taking the daily PCP, summing the days of each year. **Resource constraints:** Creative Commons Attribution 4.0 International (CC BY 4.0) **Online resources:** Download the data from Google Cloud Storage

Precipitation data is delivered on a daily basis. The source of this dataset is CHIRPS (Climate Hazards Group InfraRed Precipitation with Station) quasi-global rainfall dataset, starting from 1981 up to near present. The value of each pixel represents the daily amount of precipitation expressed in mm (1mm=1l/m² or 1mm=10m³/ha). For details see http://chg.geog.ucsb.edu/data/chirps The data is provided from January 2009 to 2024. **Data publication:** 2020-01-01 **Supplemental Information:** No data value: -9999 Unit: mm (1mm=1l/m² or 1mm=10m³/ha) Map code : L1-PCP-E Scale Factor : 0.1 Conversion factor: the pixel value in the downloaded data must be multiplied by 0.1 New dekadal data layers are released approximately 5 days after the end of a dekad. A higher quality version of the same data layer is uploaded after 6 dekads have passed. This final version of the dekadal dataset has a higher quality because gap filling and interpolation processes, where needed, have been based on more data observations. This implies that other temporal aggregations (monthly, seasonal, annual), and layers that depend on those, are updated as well. Practically this means that a final annual aggregation of the most recent full calendar year can only be produced after the end of February. Likewise, the final monthly aggregation of the most recent calendar months can only be produced 2 full months later. **Citation:** FAO 2018. WaPOR Database Methodology: Level 1. Remote Sensing for Water Productivity Technical Report: Methodology Series. Rome, FAO. 72 pages. Licence: CC BY 4.0 IGO **Contact points:** Metadata Contact: [WaPOR](mailto:wapor@fao.org) Resource Contact: [WaPOR](mailto:wapor@fao.org) **Data lineage:** Information on the methodology applied to produce CHIRPS data can be found at http://chg.geog.ucsb.edu/data/chirps.\n\nData component developed through collaboration with the FRAME Consortium. More information can be found at: http://www.fao.org/in-action/remote-sensing-for-water-productivity/en/ **Resource constraints:** Creative Commons Attribution 4.0 International (CC BY 4.0) **Online resources:** Download the data from Google Cloud Storage