Sierra Leone: Subnational Rainfall Indicators and Forecasts by Dekad

Dekadal rainfall indicators for Sierra Leone aggregated by subnational administrative units, produced by the World Food Programme (WFP). It combines CHIRPS version 2 satellite imagery with CHIRPS-GEFS forecasts to track precipitation trends and anomalies across 10-day periods.

Use Cases

• Monitoring agricultural drought by tracking the 3-month rainfall anomaly percentage (r3q)
• Comparing current 10-day rainfall (rfh) against the long-term average (rfh_avg) to identify seasonal shifts
• Evaluating the reliability of precipitation forecasts by comparing 'forecast' and 'final' entries in the type column

Strengths

• Includes 9 distinct rainfall indicators including rolling averages and anomalies
• Standardized Pcode references for subnational administrative units
• Provides data quality metadata via the n_pixels column

Limitations

• Satellite-derived estimates from CHIRPS may have inherent biases compared to local rain gauges
• Aggregated at the subnational level, which may mask hyper-local precipitation variations

Provenance

Source

World Food Programme (WFP) using CHIRPS v2 and CHIRPS-GEFS

Collection Method

Satellite imagery and in-situ station data aggregation

Freshness

Updated six times per month on a fixed schedule (1st, 6th, 11th, 16th, 21st, and 26th).

Geography

Sierra Leone