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Weather History Archive

On This Day In

                   Weather History

July 20th

Local and Regional Events:

July 20, 1951:

From the southeast residential section of Watertown, an estimated F2 tornado moved east, passing near Kranzburg and Goodwin. The storms destroyed one home and several barns. 


July 20, 2002:

An extremely strong severe thunderstorm moved over Rapid City and across the adjacent plains east of town. Downburst winds and the associated gust front caused damage along a nearly 30-mile long path. Extensive tree damage occurred throughout the eastern half of the city with countless trees and branches more than 24-inch diameter fell. Two roofs were torn off by the winds. Flying debris damaged numerous cars and buildings. The NWS office in downtown Rapid City measured an 80 mph wind gust, with meteorologists noting winds were sustained at 60 to 70 mph for 5 minutes. Ellsworth AFB wind equipment measured a 106 mph wind gust from the thunderstorm as it passed.

Local Climate Information:

Click HERE for daily climate information for Aberdeen, Mobridge, Pierre, Sisseton, and Watertown.

Click HERE for daily climate information for Sioux Falls, Huron, Mitchell, and Sioux City.


U.S.A and Global Events for July 20th:

1915: A record high temperature of 115 degrees occurred in Yosemite Valley at the National Park Headquarters, California (around 4,000 feet elevation). This reading was the warmest day in a streak of 7 consecutive days of 110 degrees or higher at Yosemite Valley from the 19th through the 25th.

Above is the Cooperative Observers’ Meteorological Record for Yosemite in July 1915. The average high temperature for the month was 104.6 degrees which were 15.4 degrees above their normal high temperature of 89.2 degrees.


1977: A flash flood hits Johnstown, Pennsylvania, on this day in 1977, killing 84 people and causing millions of dollars in damages. This flood came 88 years after the infamous Great Flood of 1889 that killed more than 2,000 people in Johnstown. Click HERE for more information from the History Channel. Click HERE for a YouTube video from WTAJ-TV.


2005: Hurricane Emily made landfall in northern Mexico. When the central pressure fell to 29.43 inches of mercury, and its sustained winds reached 160 mph on the 16th, Emily became the strongest hurricane ever to form before August, breaking a record set by Hurricane Dennis just six days before. It was also the earliest Category 5 hurricane ever recorded in the Atlantic basin, beating Hurricane Allen's old record by nearly three weeks.

Click HERE for more This Day in Weather History from the Southeast Regional Climate Center.