| U.S. Department of Agriculture National Agricultural Statistics Service Research and Development Division |
| Continental US | US w/Average 1st Frost | 9 Period US Thumbnail | Pacific NW |
| KS/OK | ND/SD/MN | IL/IN/IA/MO | TX/LA |
| Southeast | California/Nevada | Miss. Delta | |
| Northeast | Southwest | Nebraska |
| Biweekly NDVI | Biweekly NDVI w/Frost |