WASHINGTON -- The drought has intensified in the most parched areas of the country, with more than a fifth of the contiguous United States experiencing ‘‘extreme’’ or ‘‘exceptional’’ drought, according to numbers released Thursday by the National Drought Mitigation Center.

As lawmakers scrambled Thursday to put together a bill giving disaster relief to ranchers, much of the Great Plains continued to fry under cloudless skies. Nebraska, Kansas, Missouri, Oklahoma, and Arkansas are experiencing intensifying drought.

‘‘It’s hard to believe that it’s getting worse, but it is, even with some rain in the region,’’ said climatologist Brian Fuchs in a statement released by the drought center.

The geographical expanse of the drought has shrunk very slightly, but the area affected remains historically broad, with more than three-fifths of the lower 48 states experiencing moderate drought or worse. That area comes close to matching the sprawling drought of 1934 at the worst of the Dust Bowl era.

The House on Thursday raced to pass $383 million in relief that could provide up to $100,000 each for the hardest-hit livestock producers.

That bill would still have to pass the Senate and might not become law until sometime this fall.