ST. LOUIS (AP) — The nation’s worst drought in decades consumed a larger portion of the lower 48 states last week with the Midwest corn harvest in full swing, according to the latest update by a drought-tracking consortium released Thursday.

The U.S. Drought Monitor’s new map shows 65.5 percent of the contiguous U.S. experiencing some form of drought as of Tuesday, creeping up from 64.8 percent a week earlier. The portion of the U.S. in extreme or exceptional drought — the two worst classifications — rose three-quarters of a percentage point to 21.5 percent.