ST. LOUIS (AP) -- The snowstorm that pummeled the upper Midwest last week is helping ease dry conditions in Iowa but hasn't done much to relax the overall grip of the worst U.S. drought in decades.

The weekly U.S. Drought Monitor report released Thursday shows that roughly 62 percent of the continental U.S. remains in some form of drought, unchanged from the previous week. That number has been above 60 percent largely since July.

Nearly 22 percent of the lower 48 states are in extreme or exceptional drought, the two worst categories. That also is unchanged from the previous week.

All of Iowa, Kansas, Nebraska, Oklahoma and South Dakota are in drought. But thanks to last week's snow, the amount of Iowa in extreme or exceptional drought fell 9 percentage points to 32 percent.