The Map shows, in varying shades of red, the percentage reduction in cumulative Enhanced Vegetation Index (EVI) for the months of May through August compared to the four-month period averaged over six years, 2000-2005.

EVI reveals both the vigor of plant growth and its biomass accumulation. Vegetation growth is mostly limited by water, so the below average EVI growth during the growing season is a good indicator of drought.

Data Sources
The data originated from the MODIS (Moderate Resoulution Imaging Spectometer) sensor onboard the Nasa's Terra Satellite. The data are available at 500m spatial resolution on 16-day intervals.

The region also received below average precipitation during the growing season. The Precipitation Anomaly map shows the change in cumulative precipitation for the months May through August 2006 compared with the longterm average (1971-2000).

Data Sources
Time bias corrected Climate Division precipitation data are obtained from National Climate Data Center and interpolated using Cressman interpolation method. Climate Division data are available here.