This year's record-breaking drought grew worse in the Great Plains and spread across the United States as a whole, despite the rain dumped on parts of the South and Midwest by Hurricane Isaac.

Isaac's slow-moving rains brought relief to parts of Louisiana, Arkansas, Missouri, Illinois, Indiana and Ohio, according to the latest U.S. Drought Monitor released today.

But northwest Arkansas and southwest Missouri missed out. Meanwhile, "exceptional" drought conditions spread across nearly all of Nebraska and extended into Wyoming, South Dakota, Iowa and Kansas.

Drought afflicts 53 percent of the United States, up from 52.6 percent last week.

"We're seeing fires due to the dryness in northwest Nebraska and into South Dakota," said Brian Fuchs, a climatologist at the National Drought Mitigation Center at the University of Nebraska, Lincoln, and U.S. Drought Monitor author.

Extreme drought receded in the Four Corners region of Utah and Colorado, due to a consistent wet pattern, Fuchs said.

Patterns in place now are likely to persist, according to Fuchs.

The forecast "shows improvements over the southwestern U.S., especially in Arizona and the Four Corners region," he said. "But drought is likely to persist through much of the Great Basin, Rocky Mountains, and central and southern Plains. It'll keep improving over the Midwest and Southeast and New England. Drought will persist and develop throughout the Hawaiian Islands."