Heat in Maryland, June 7 to 9, 1999

High pressure centered over the Southeast U.S. caused air to downslope over the Appalachian Mountains, sending afternoon temperatures into the upper 90s to lower 100s. The heat, in combination with very humid air, resulted in afternoon heat indices between 100 and 110 degrees. Record high temperatures were set at Baltimore/Washington International Airport (BWI) on the 7th, 8th, and 9th. High temperatures on the 7th included 96 degrees at BWI, 98 degrees at the Maryland Science Center in downtown Baltimore, 95 degrees at Sharpsburg in Washington County, 97 degrees at Oxon Hill in Prince Georges County, and 100 degrees at Williamsport in Washington County. Highs on the 8th included 97 degrees at BWI, 98 degrees in downtown Baltimore, 97 degrees at Oxon Hill, and 95 degrees at Sharpsburg and Williamsport. Highs on the 9th included 96 degrees at BWI, 95 degrees in downtown Baltimore, 96 degrees at Cumberland, 98 degrees at Oxon Hill, 97 degrees at Bryans Road, 96 degrees as Sharpsburg, and 104 degrees at Williamsport. Nighttime lows dipped into the 70s, except the lower 80s in downtown Baltimore, making the overnight hours very uncomfortable for those without air conditioning. As a result of the heat, a pollution alert was issued for the Washington D.C. metropolitan area on the 7th. Air conditions reach "Code Red" levels two days in a row. Schools without air conditioning in the City of Baltimore, Prince Georges County, and Anne Arundel County cancelled classes. Area hospitals reported treating a handful of people for heat related illnesses , including a hospital in Anne Arundel County that admitted a patient for heat related dehydration. Several locations reported near record water and energy consumption during the period.