Iran: Subnational Dekadal Rainfall Indicators and Forecasts

Dekadal rainfall indicators for Iran's subnational administrative units are provided by the World Food Programme using CHIRPS satellite imagery and CHIRPS-GEFS forecasts. The data includes 10-day, 1-month, and 3-month rainfall totals, long-term averages, and percentage anomalies. Observations are updated multiple times per month to transition from forecasts to final validated products.

Use Cases

• Drought monitoring using the rainfall anomaly percentage (rfq) column to identify moisture deficits
• Agricultural planning by comparing current 3-month rainfall (r3h) against long-term averages (r3h_avg)
• Validation of weather models using the type column to compare initial forecasts against final observations

Strengths

• Includes 3-month rolling averages (r3h) for seasonal trend analysis
• Uses standardized WFP Pcode references for administrative unit identification
• Provides pixel counts (n_pixels) to indicate the spatial data density for each unit aggregation

Limitations

• Satellite-derived CHIRPS data may differ from local rain gauge measurements in complex terrains
• Finalized data for a given month is only available mid-way through the following month

Provenance

Source

World Food Programme (WFP) using CHIRPS and CHIRPS-GEFS data from Climate Hazards Group

Collection Method

Aggregation of satellite imagery (CHIRPS v2) and station data into administrative units

Freshness

Updated six times per month following a specific forecast and observation release cycle

Geography

Iran (Islamic Republic of)