NDVI data calculated from the AVHRR sensor on the NOAA-17 satellite are
used to create vegetation condition imagery beginning in April of the 2004
crop season. The images selectable below include displays of the NDVI index
for various US areas. Since NOAA-17 AVHRR may not be directly comparable to NOAA-16, no
ratio images to previous years are shown. Agricultural Statistics District
(ASD) and/or county boundaries are shown where the resolution allows.
Thumbnail images, which start when at least eight prior periods are available,
allow season to-date review. US images with average first frost isolines
overlaying NDVI are available starting with the period containing September
1st. Select a GIF or PDF image to view from the tables below. Images are in
GIF format unless otherwise noted.