KANSAS CITY — Areas of extreme and exceptional levels of drought in the High Plains expanded in the latest week, according to the most recent data from the U.S. Drought Monitor released today.

The Monitor, published each Thursday based on data through Tuesday by the National Drought Mitigation Center at the University of Nebraska-Lincoln, said that in Kansas, Nebraska, Colorado, Wyoming, North Dakota and South Dakota, extreme drought expanded to 57.89% of the region, up from 55.94% in the previous week. Exceptional drought, the most severe description used by the Monitor, expanded to 26.72% of the area, up from 26.28% a week ago and nearly twice the 14.97% in extreme drought three months ago.

The U.S. winter wheat crop in the 18 major growing states had record low (for the date) condition ratings of 33% good to excellent, 41% fair and 36% poor to very poor as of Nov. 25, according to the U.S. Department of Agriculture’s latest Crop Progress report. The crop was 88% emerged in the 18 states with plants entering or near winter dormancy in some areas.

Observers of the current winter wheat crop are paying close attention to the scope of the drought because it is affecting growth prospects of the crop, especially in the hard red winter region, although analysts have noted spring rains are more important than fall crop ratings in determining the final yield and quality of winter wheat.

The Drought Monitor map shows that Nebraska is almost entirely in extreme and exceptional drought. In the U.S.D.A.’s latest Crop Progress report, Nebraska’s winter wheat crop was rated 46% poor to very poor, 40% fair and only 14% good with none of the crop considered excellent.

Top wheat producer Kansas’ drought situation is less severe than Nebraska’s, with most exceptional drought in the northwest quadrant of the state and south central and much of the rest of the state in extreme drought. Winter wheat conditions in Kansas were rated 29% good to excellent and 46% fair in the latest Crop Progress report.

Conditions, though, worsened in parts of Kansas. Commenting on current weather conditions in the High Plains, the Drought Monitor reported “unseasonably mild, dry conditions maintained or increased drought across much of the region, although a swath of light to moderated snow afforded localized drought relief in southwestern South Dakota. The most notable changes were the expansion of exceptional drought in southern Kansas as well as an increase in severe to exceptional drought in central and northeastern South Dakota. Over the past 90 days, rainfall has totaled less than 25% of normal from south-central Nebraska northward into central South Dakota.”

In the region that the Drought Monitor designates as the Midwest — from Minnesota south to Missouri and east to Ohio and Kentucky — drought conditions were reported to be much more moderate than in the High Plains. This section of the United States includes the major soft winter wheat growing Central states of Missouri, which had 53% of its crop rated in good-to-excellent condition, Illinois with 69% good to excellent, Indiana with 72% and Ohio with 70%, according to the U.S.D.A.

The U.S. Drought Monitor is jointly produced by The National Drought Mitigation Center and the University of Nebraska-Lincoln, the National Oceanic and Atmospheric Administration, the U.S.D.A. and about 350 drought observers across the country.