The latest update on the nation's worst drought in decades shows that farmers bringing in their weakened corn crops caught some relief with recent rains that soaked much of middle America.

The weekly U.S. Drought Monitor map released Thursday shows two-thirds of Iowa now in extreme or exceptional drought, the two worst categories. That's because the amount of that state in extreme drought rose slightly while the swath in exceptional drought remained unchanged at 2.4%.

The worst two drought categories held steady in Nebraska, at 97.4% of the state, and were nearly unchanged in Illinois, at 6.67%. Missouri's numbers dropped more than 6%age points, to 25.20%.

The land area in the lower 48 states in extreme or exceptional drought remained at about 21%.