Heat in Virginia, July 20 to 23, 1998

After an unusually pleasant start to the month, a singular heat wave affected northern Virginia during the climatological peak of highest annual temperatures. The heat wave, caused by the combination of hot and humid air associated with "Bermuda" high pressure and increasingly dry ground, caused temperatures to soar into the mid and upper 90s. The heat index, however, equalled or exceeded 100 each afternoon. Highest temperatures were recorded in the Shenandoah Valley on the 22nd, with Winchester and Luray (VAZ028>029) each reaching 99 degrees and Charlottesville (VAZ037) reaching the century mark. A record high was observed at Washington/Dulles International Airport (VAZ042) on the 22nd when the temperatures soared to 98 degrees. The heat wave was less tolerable than those in recent years since much of the summer had been cooler and less humid than normal.Across northern Virginia, five persons required brief hospital visits due to heat exhaustion; four in Fairfax Co (VAZ053) and one in Prince William Co (VAZ052). Virginia Power reported record usage on the 22nd; the nearly 16,000 megawatts of emitted power surpassed the day-old record of 15,010. The previous record had been 14,910 megawatts.The heat wave broke during the evening of the 23rd with the passage of a cool front.