The record-breaking drought -- an expansion of a Southern drought that began in 2010 -- combined with record-high temperatures to roast millions of acres of Midwest and Great Plains corn and soybeans, and scorch comparable swaths of grasslands and pastures needed for cattle grazing, the National Drought Mitigation Center at the University of Nebraska-Lincoln said.
This is the hottest year on record in the lower 48 states, government meteorologists say.
"It's hard to believe that it's getting worse, but it is," U.S. Drought Monitor climatologist Brian Fuchs said.
"We saw drought continue to intensify over Nebraska, Kansas, Missouri, Oklahoma and Arkansas this week," he said. "Pretty much all of Kansas, Missouri and Nebraska are now in extreme drought, and it expanded through much of Oklahoma."
Good rains in parts of eastern Tennessee, West Virginia, west Texas and northern Colorado brought some relief, he said.
But he said the drought was forecast to persist over much of the country through October, which analysts have said would send U.S. and overseas food prices surging.
A Drought Monitor map from three weeks ago indicated the portion of the lower 48 states receiving the two most serious drought designations stood at 11.6 percent. That area has now nearly doubled to 21.5 percent, the center said.
As of July 31, 38.12 percent of the nation was in severe drought or worse, compared with 38.11 a week earlier; 18.62 percent had extreme drought or worse, compared with 17.2 percent the week before; and 2.52 percent experienced exceptional drought, up from 1.99 percent the preceding week, the center said.
The portion of the United States and Puerto Rico in moderate drought or worse was 52.65 percent, down from 53.44 percent the week before, the center said.
The drought is also hurting Canada's corn and soybean crops, while heat waves across Europe are also destroying cash crops. South American farmers, with ample rain, are planting record amounts of corn and soybeans, officials said.
On Capitol Hill, House Republicans Thursday passed, by a vote of 223 to 197, a short-term $383 million package of loans and grants for some drought-stricken livestock producers and farmers.
But Democratic leaders in the Senate, which passed a bipartisan five-year agricultural policy omnibus farm bill June 21, said they wouldn't rush through the House measure simply because they were getting ready to begin their five-week summer recess.
They blamed House Republican leaders for failing to consider the broader legislation early enough.
The end result was that Congress likely take no action to provide drought aid before breaking for a five-week summer recess, The New York Times reported.
"I'm not passing a bill that only covers some producers," said Senate Agriculture Committee Chairwoman Debbie Stabenow, D-Mich.
"I appreciate the first step and I certainly understand that the agriculture chairman in the House is trying to do whatever they can take that step," she said. "But it does not cover every kind of disaster we have before us, and frankly does not cover disasters waiting to happen because of inaction."
House Speaker John Boehner, R-Ohio, acknowledged the House version of the five-year farm bill -- which deals with agriculture and related issues under the U.S. Department of Agriculture -- had become in a problem his chamber.
He cited the Supplemental Nutrition Assistance Program -- more commonly known as food stamps -- which the House Agriculture Committee proposed cutting by $16.5 billion over 10 years to protect agriculture subsidies.
The cuts -- more than triple the $4.5 billion approved in the Senate -- would deny 2 million to 3 million people food assistance of $90 a month per family and end free school meals for 280,000 children.
"With the farm bill, I've made pretty clear that the House is pretty well divided," Boehner said.
"You've got the left concerned about reductions in the food stamp program. You've got the right, who don't think the cuts go far enough in the food stamp program to bring it into compliance with what the law asked them, and frankly, I haven't seen 218 votes in the middle to pass a farm bill," he said.