This Day in Weather History May 15
National Oceanic and Atmospheric Administration
2001: Very hot weather pushed the temperature all the way up to 101 F at Sioux City making this the earliest date of the year on which such a high temperature has ever been recorded in Iowa.
1998: A severe weather outbreak produced 13 tornadoes across Iowa including an F3 that injured 47 people in and around Washington. Severe weather was reported in at least 43 counties across the state.
1997: A very late light snow fell in a few areas of far northeastern Iowa with traces recorded at Cresco, Decorah, Lansing, and Waukon.
1968: A major tornado outbreak across the central U.S. resulted in what was probably the worst tornado day of the 20th century in Iowa. During the morning hours large hail was reported across the eastern half of the state with stones up to 2.5 to 3 inches in diameter reported at several locations. Later in the afternoon multiple tornadoes struck northeastern Iowa including two extremely violent F5 tornadoes. One of these moved from near Hansell in Butler County through Chickasaw, Floyd, and Franklin and into Howard County, dissipating just south of the Minnesota border near Chester. The large tornado passed directly through Charles City where it destroyed more than 350 homes and businesses. The smaller town of Elma to the northeast was also struck and suffered heavy damage. This tornado was on the ground for 65 miles, destroyed nearly 2000 homes, and resulted in 15 fatalities and more than 450 injuries with most of those occurring in and around Charles City. The other violent F5 tornado that afternoon moved directly through Oelwein and Maynard before dissipating near Randalia in Fayette County, killing 5 people and injuring more than 150 while destroying nearly a thousand homes along its path. “The Charles City tornado” is still remembered to this day by many long-time Iowa residents and their descendants.
1907: A very warm March in Iowa was followed by an exceptionally cold and snowy late spring with Des Moines experiencing its coldest April and coldest May on record. This sudden shift was likely caused by the powerful eruption of the volcano Ksudach in eastern Russia in late March of 1907, which threw ash high into the atmosphere partially blocking incoming sunlight for several months. April ended with a winter storm on the 28th-30th, then another storm system spread snow across nearly all of Iowa on May 3rd, and finally on the 15th the latest statewide snowfall on record occurred. Accumulations were quite light due to warm surface temperatures with an observer at Estherville noting that “there was a heavy snowstorm all day, which melted as it reached the ground”. An observer at Boone wrote that “it began snowing at 8:15am and was raining, snowing and sleeting at times during the day”. A tenth of an inch of snow was recorded at Des Moines making this the latest date on record that measurable snow has ever fallen at that location. Other reported accumulations included 0.2 inches at Denison, 1.0 inches at Algona, 2.0 inches at Rockwell City, and an amazing 5.0 inches at Rock Rapids. The only appreciable snowfalls ever to occur in Iowa on a later date in the year were the incredible events of May 23, 1882 and May 28, 1947.
Source: National Weather Service
