Floods: The Mall is always at risk of flooding since sections of it are built over old creek beds, canals, and a tidal marsh, and the land borders the Potomac River. During the 1800s, heavy rains could flood the train tracks that crossed the Mall. In June 1889 a major storm caused significant flooding in the city and the Mall where water was as deep as 2 feet; this map shows how widespread the flooding was. Today there are levees to help prevent severe flooding on the Mall.

Tornadoes: The first recorded severe storm struck the Mall in August 1814, before buildings filled the Mall. On September 16, 1888, a tornado damaged the National Museum and the Botanic Garden greenhouses, and an area housing sea turtles at the Fish Commission. In September 2001, a tornado with winds up to 112 mph crossed into Washington from Virginia across the Memorial Bridge. Luckily the tornado weakened by the time it reached the Washington Monument, leaving only a few broken tree branches in its wake. 

Dust Storms: In the 1930s, the Mall experienced very unusual dust storms. Western states experienced massive soil erosion and drought in the 1930s known as the Dust Bowl that caused devastating storms. In May 1934, a thick cloud of dust blew in from Texas and Oklahoma covering the east coast from Washington north to Canada. In March 1935 another storm blanketed the city just as Congress was hearing testimony from the director of the Soil Erosion Service. A deep layer of dust coated the ground and monuments of the Mall for days.

Blizzards: The Knickerbocker Snowstorm of 1922 was among the fiercest blizzards to shut down the National Mall. So-called because the collapse of the roof of the nearby Knickerbocker theatre killed 98 people, the storm shut down the Smithsonian Institution for days. In 1979 a Presidents' Day blizzard stopped a group of farmers and their tractors from protesting on the Mall. When the snow hit, the farmers helped Washingtonians by using their tractors to dig out cars, take stranded workers home, and transport doctors and nurses to hospitals.

Earthquakes:  Washington has not been the epicenter for any earthquakes but the area has experienced tremors and damage from earthquakes. In 1828, President John Quincy Adams felt an earthquake centered in southwestern Virginia while sitting at his desk in the White House. An 1884 earthquake centered near Columbus, Ohio was felt by men working on the Washington Monument. In August 2011, a 5.8- magnitude earthquake centered in Virginia caused structural damage to many Washington buildings including the Washington Monument. The damage was so serious that the Monument was closed to visitors for three years.