KANSAS CITY, Missouri (Reuters) - Hot and dry conditions continued to plague large parts of the U.S. Plains and southern states as the worst U.S. drought in over five decades expanded its grip on some key farming states.
At least "moderate" levels of drought have now enveloped more than 64 percent of the contiguous United States, up from 63.39 percent the week before, according to the Drought Monitor, a weekly compilation of data gathered by federal and academic scientists.
"This is the greatest extent of drought we've seen all summer," said Brian Fuchs, a climatologist at the National Drought Mitigation Center at the University of Nebraska-Lincoln. "The drought is easing in the east, but we're seeing more of it expand in the Central Plains, Rockies and Dakotas."
The Drought Monitor's measurement of the worst level of drought, "exceptional", expanded to 6.23 percent of the land area in the contiguous U.S. for the week ended September 11, up from 6.14 percent in the prior week.
The drought has been exacerbated by long stretches of high temperatures.
"That has been the kicker all summer, how hot it has been," said Fuchs.
Conditions in Texas, Oklahoma, Kansas, Nebraska, Colorado, and Iowa grew more dire, according to the Drought Monitor.
Kansas, in particular, remained almost entirely parched, with more than 60 percent of the state in exceptional drought and more than 88 percent in extreme drought.
The climatologists noted "widespread expansion" of severe drought in western North Dakota and said the percent of normal precipitation has held below 50 percent throughout most of the Northern Plains over the last month.
On a bright note, the levels of drought considered "severe" and "extreme" did ease in the most recent week across the nation. The portion of the contiguous United States suffering from at least "severe" drought fell to 41.81 percent from 42.48 percent.
The area experiencing "extreme" levels of drought dropped to 21.09 percent from 21.45 percent.
Arkansas, one of the hardest hit states, saw drought start to recede as the percentage of the state in severe or worse drought dropped to 75.72 percent from 78 percent. Missouri, likewise, saw improvement, as did Illinois.
This year's persistent high heat and lack of soil moisture have decimated the U.S. corn crop, and threaten the same to the soybean crop. Dry soils are also worrying wheat farmers who now must seed a new winter wheat crop.
The U.S. Agriculture Department on Wednesday estimated that the U.S. corn crop will be the lowest in six years and soybeans the lowest in nine years due to drought losses.
Some rainfall relief may be coming, particularly to areas of Texas and Oklahoma. Portions of drought stricken Colorado, Kansas and Iowa are expected to receive some modest relief, forecasters said.
(Editing by Carol Bishopric)