The drought that has plagued the southeastern United States this spring and summer has been spreading northward gradually into Maryland. Last week, 37 percent of the state was in what the U.S. Department of Agriculture considers "moderate" drought. With the issue of the new Drought Monitor map yesterday, the percentage of the state in moderate to "severe" drought has expanded to almost 85 percent.

(7/26 NOTE: That 85 percent figure is incorrect. The actual number is 75 percent. We misinterpreted a data table from the USDA and, somehow, nobody called us on it. The error was discovered this morning. We're fixing it now in Thursday's Web story.  Your WeatherBlogger regrets the error.)

(Drought conditions are determined by a complex formula that takes into account measurements of soil moisture, streamflow, precipitation and the health of vegetation as measured by satellite imagery.)

 Here's the national map. It shows almost the entire nation east of the Mississippi enduring  unusually dry weather, as are the far Western states. Only the nation's midsection is enjoying more or less normal rainfall and soil conditions. 

The state's worst conditions have settled over Southern Maryland, including Charles, St. Mary's and southern Calvert counties, all now in a severe drought. Here's the state map.

Moderate drought conditions prevail from eastern Allegany County, across much of central Maryland, including Baltimore and southern Baltimore County, to the lower Eastern Shore. The rest of the state - including far western Maryland and the northeast corner (from northern Carrol, across northern Baltimore, Harford and Cecil counties) - is rated "abnormally dry."

It is the most widespread drought in Maryland since October 2005, when the entire state was in moderate drought.