Hottest and Coldest Temperatures Ever in Washington DC on June 30

On June 30th in Washington D.C., the hottest temperature ever recorded was 100.0°F in 1959, while the coldest temperature was recorded at 59.0°F in 1988. The average temperature for this date stands at 77.84°F, with an average high of 81.21°F and an average low of 74.47°F. In the year 1959, when the highest temperature was recorded, an interesting news item was the ascent of the USS Skate, the first submarine to surface at the North Pole.