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30 Day Rain / Dry Days and Anomalies

Continental Africa

Number of Rain Days & Anomaly
Consecutive Dry Days & Anomaly
Total Rainfall & Anomaly
Days Since Rain & Anomaly

Daily Period

Available Tools


The GeoWRSI is a geo-spatial, stand-alone implementation of the Water Requirements Satisfaction Index (GeoWRSI), as it is implemented by the USGS for the FEWSNET Activity. The program runs a crop-specific water balance model for a selected region in the world, using raster data inputs. The program produces a range of outputs which can either be used qualitatively to help assess and monitor crop conditions during the crop growing season, or can be regressed with yields to produce yield estimation models and yield estimates. Other tools are available to post-process the GeoWRSI outputs so that they can be used in yield estimation models.


The GeoCLIM is a spatial analysis tool designed for climatological analysis of historical rainfall and temperature data. The GeoCLIM provides non-scientists with an array of accessible analysis tools for climate-smart agricultural development. These user friendly tools can be used to obtain and analyze climate data, blend station data with satellite data to create more accurate datasets, analyze seasonal trends and/or historical climate data, create visual representations of climate data, create scripts (batch files) to quickly and efficiently analyze similar “batches” of climate data, view and/or edit shapefiles and raster files, and extract statistics from raster datasets to create time series.


The Early Warning eXplorer (EWX) software is an interactive web-based mapping tool that allows users to visualize continental-scale rainfall estimate (RFE), land surface temperature (LST) and normalized difference vegetation index (NDVI) data and anomalies at varied time steps and review time series analyses.

EWX Lite

The Early Warning eXplorer (EWX) Lite software is an interactive web-based mapping tool that allows users to visualize time series of rainfall, NDVI, evapotranspiration, land surface temperature and snow water volume, where applicable. The EWX Lite allows users to access the same time series database that drives the standard EWX without having to load raster imagery which can inhibit performance in areas with poor internet connectivity.

Product Documentation

Daily 30-day Rain and Dry Days and Anomalies
(updated May 7, 2010)

This page contains 4 pairs of graphic images. Each graphic consists of a data image (left image) and its anomaly image (right image). The anomaly image is the difference between the current day's image and the average for that day from 2001 through 2009.

The upper left image pair is the number of days, during the last 30 days, in which at least 1 mm of rain fell and its anomaly. That is, a 'rain day' was defined as a day in which the rainfall amount was greater than or equal to 1 mm.

The upper right image pair is the maximum number of consecutive dry days in the past 30 days and its anomaly, where a 'dry day' was defined as a day in which the rainfall amount was less than 1 mm.

The lower left image pair is the total accumulated rainfall amount over the past 30 days and its anomaly.

The lower right image pair is the number of days since a 'rain day' and its anomaly, that is, the number of days since rainfall was 1 mm or greater for a day.

The input data for each day of a 30-day cycle is the daily Rainfall Estimate (RFE) as provided by NOAA CPC.