No relief in sight for drought-stricken U.S. Plains

* Plains wheat belt continues to struggle

* No significant rain or snow expected

* Arctic cold early next week in north U.S.

CHICAGO, Jan 18 (Reuters) - Dry weather should continue through at least the end of January in the drought-stricken U.S. Plains and a blast of Arctic cold air in the Midwest early next week poses a threat to unprotected livestock and possibly some wheat, an agricultural meteorologist said on Friday.

"The hard red winter wheat belt in the Plains looks quiet, dry and cooler next week, but there shouldn't be a cold air threat in the Plains," said John Dee, meteorologist for Global Weather Monitoring.

Dee said temperatures would fall to zero (degrees Fahrenheit) or below early next week in the northern Midwest, roughly north of Interstate 80. Coldest readings will be in the northern states of North and South Dakota, Minnesota, Wisconsin, northern Iowa, Illinois and Michigan.

"There's not a lot of snow cover so there is the potential for some damage. Zero readings could reach as far west as Nebraska," he said.

Commodity Weather Group (CWG) on Friday said most of the United States remained dry near the end of the week and showers next week would be limited to the eastern Midwest.

"Drought relief will be limited," said Joel Widenor, CWG meteorologist.

Cold air will push into the U.S. early next week and again late in January but the cold snaps do not appear to be strong enough to damage either U.S. wheat or Florida citrus, according to CWG's Friday report.

A series of rain showers helped ease drought conditions in parts of the United States over the last week, but drought expanded slightly in parts of the U.S. Plains, according to a report issued on Thursday.

Officials in north-central Oklahoma declared a state of emergency due to record-low reservoir conditions. Public and private interests throughout the central United States hardest hit by drought were examining measures to try to cope with ongoing drought.

The government declared much of the central and southern U.S. Wheat Belt a natural disaster area on Wednesday last week due to persistent drought threatening the winter wheat harvest.

In its first disaster declaration of the new year, the Agriculture Department made growers in large portions of four major wheat-growing states - Kansas, Colorado, Oklahoma and Texas - eligible for low-interest emergency loans.

(Additional reporting by Carey Gillam in Kansas City; Editing by Dale Hudson)