On May 29, 1909, an F3 (possibly F4) tornado struck Cavalier county and moved through the Langdon area. 17 homes and 40 other buildings were destroyed in Langdon. This tornado killed 5 and injured 30, and had a path length of around 7 miles. There were also 2 other F3 tornadoes on this day in our area, one in Richland county and another in Stutsman county.
Below is an image created from the rudementary surface network that was in place across the county is 1909. Only a handful of regular observations were available, yet remarkably accurate and relatively detailed weather maps were available for the time. Looking at the image below, a strong low pressure system, typical in late spring across the plains, had brought a very warm and moist airmass north into the North Dakota region from the Gulf of Mexico. As is often the case, this set the stage for the strong thunderstorms that produced the tornadoes across the region that day. (Click on the map for a larger version).