From NWS
2004: A severe weather outbreak occurred for the second consecutive day with storms developing on the afternoon of May 22nd and continuing into the morning of the 23rd, producing at least 20 tornadoes across Iowa. Fortunately most of these were relatively weak and affected open country with no injuries occurring. Some of the storms produced very large hail including incredible 5.5 inch diameter stones just northwest of Slater. Some storms also produced very heavy rain and flooding with accumulations of 5.20 inches at Colo and 6.67 inches near Ames. At Waterloo a total of 6.96 inches of rain fell in four days from May 21-24, and by the end of the month their total of 11.39 inches broke the record for the wettest May on record at that location.

1873: Severe weather struck southeastern Iowa as a tornado tore a path through Keokuk, Washington, and Louisa counties before crossing into Illinois. Very large hail fell along its track with hail stones 4.5 inches in diameter found at Sigourney and stones as large as hen eggs picked up in Washington four hours after the storm. The storm killed 8 people and injured at dozens of others in Iowa. The worst destruction occurred north of Washington when the tornado was a half mile wide and produced F4 damage at times, including at a school six miles north of town where a student and teacher were killed and eight other students seriously injured. The U.S. Army Signal Corps, ancestor of the modern day National Weather Service, conducted the first ever detailed tornado damage survey following this storm.

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From NWS

2004: A significant severe weather outbreak began on the morning of May 21st and continued into the morning of the 22nd producing 16 tornadoes across Iowa including one that injured 15 people in and around Bradgate. Large hail was reported across the state including at Spencer where softball sized hail fell twice, first with a storm around 10 am then again with another storm around 4 pm. Some of the storms also produced very heavy rainfall and flooding with accumulations of 4.75 inches at Emmetsburg, 5.14 inches at Decorah, and 6.10 inches at Mason City.

1918: A significant tornado outbreak occurred with at least 19 touching down in Iowa, including a particularly violent tornado that leveled farms on a path from near Denison through Carroll County to around Stanhope. As it passed through southeastern Webster County this storm nearly destroyed the small towns of Harcourt and Dayton and severely injured a number of children when their school wagon was struck. Another tornado touched down intermittently from near Berkley in Boone County to Wellsburg in Grundy County, killing 10 people and injuring nearly 100. A third storm struck areas around Newton and Kellogg killing several people and injuring dozens of others. In total approximately 19 people were killed and over 150 injured across Iowa.

1902: A burst of very heavy rain fell around and just north of Decorah during the early morning hours. Officially 3.35 inches of rain was measured in Decorah, but there were estimates of as much as six inches falling in a short time a few miles north of town. This brief downpour produced a severe flash flood which swept through the area damaging dozens of homes and killing at least three people. Large sections of railroad track and nearly all of the bridges in the area were destroyed or severely damaged with virtually all communication and transportation to and from the town cut off. Newspaper accounts indicated that the water rose very rapidly, with many creeks and streams jumping out of their banks within 30 minutes of the rainfall and the water sweeping through Decorah “at terrific speed”. One house was carried three blocks by the flood, with the family inside escaping by cutting a hole in the roof and climbing into the second story of another residence against which theirs had lodged.

21 May 1857 → In Baghdad, Iraq a dust storm lasted the entire day. Then at about 5 pm, a darkness set in, deeper than the darkest night, and terrorized local residents. 21 May 1918 → An F5 tornado swept foundations bare along a 37 mile path from Carroll County to Webster County, IA. Mattresses were found two miles away, and 4 people were killed. 21 May 1950 → A tornado was on the ground for 66 miles from Buckinghamshire to Cambridgeshire, resulting in the longest track of any English tornado.

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From NWS
1892: May was a very wet month with Des Moines recording precipitation on 23 days and significant flooding occurring across Iowa. Late on the 19th a cold front moved across the state bringing in unseasonably cool air. Remarkably, temperatures fell enough to allow light snow and sleet to mix with rain at times across nearly the entire state on the 20th making this one of the latest instances of Iowa snowfall on record. At most locations where sleet and snow were observed only a trace was reported as ground temperatures did not allow for accumulation. Stations reporting traces of snowfall included Clarinda, Corning, Cedar Rapids, Centerville, Des Moines, Glenwood, Indianola, Keosauqua, Logan, Oskaloosa, and Sac City along with numerous other towns. The observer at Logan noted that “there was quite a storm of hail and snow on the 20th, melting as it fell.” Across northern Iowa where ground temperatures were slightly cooler measurable snow was recorded at three stations with 0.1 inches at Algona and 0.3 inches at Osage and Storm Lake. Further north measurable snow fell across much of Minnesota with several inches reported in some areas including the Twin Cities, making this the latest measurable snowfall on record at that location. Only the amazing storm of May 28, 1947 produced a later widespread snowfall in Iowa, and May of 1892 remains the wettest May on record in the state.

20 May 1957 → An F5 tornado touched down southwest of Kansas City, then traveled 71 miles through the suburbs. The tornado killed 45 people and left a path of near-total destruction in its wake. All that remained at one house was a small table with a fish bowl sitting on top, with the fish still swimming inside. A canceled check from Kansas City was blown all the way to Ottumwa, IA, a distance of nearly 200 miles. 20 May 1996 → In Niagara, Ontario a tornado struck a drive-in theater that was about to show the feature movie, Twister.

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From NWS
1911: Severe thunderstorms affected several areas around Iowa. At Charles City a downpour dumped 1.24 inches of rain in a very short time with 0.55 inches of that falling in just five minutes. At Boone an observer wrote that ‘hailstones as large as hen’s eggs broke thousands of window lights, damaged roofs and killed birds.’ Further east a severe storm produced destructive straight line winds in western portions of Cedar Rapids, destroying several buildings and significantly damaging many others. An observer reported that ‘the gale swept with resistless force, trees were snapped and twisted off as easily as if they were made of glass. Wires were tangled and broken, putting the telephone and light service completely out of commission. Barns were unroofed, and doors and trees were scattered all along the boulevard.’ Several people were injured in Cedar Rapids, one seriously, but there were no fatalities reported.

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From NWS
1997: A severe thunderstorm produced very large hail in and around Iowa City where stones larger than baseballs caused more than 40 million dollars in damage in just 15 minutes. Hail as large as 4.5 inches in diameter fell further northeast around Hopkinton.

1990: Slow moving thunderstorms produced 4 to 8 inches of rain around Sioux City resulting in a record crest more than 7 feet over flood stage on Perry Creek. This flash flood caused the evacuation of about a thousand homes and produced at least 4.5 million dollars in damage. There was also flash flooding in Crawford and Plymouth counties, with a hundred hogs killed on one farm near Denison as 8 to 10 feet of water flooded a barn after 3.5 inches of rain fell in just over an hour.

1934: One of the hottest summers on record in Iowa began in earnest with very hot May temperatures reaching 104 F near Inwood on the 18th. Other high temperatures that day included 102 F at Spencer, 101 F at Rock Rapids, and 100 F at Pocahontas. At Des Moines the month would finish as the warmest May on record with an average temperature of 71.1 F.

1898: A severe thunderstorm produced a long-lived violent tornado and very large hail as it tracked from Cedar County through Clinton and Jackson counties then crossed the Mississippi River into Illinois. The storm killed 19 people and injured at least 40 others in Iowa with another 9 killed and more than 100 injured in Illinois. Amazingly the tornado grazed more than a dozen towns along its path but failed to directly strike any of them, otherwise the casualties would likely have been far more numerous. Many lives also appear to have been saved by the fact that the tornado moved unusually slowly, traversing the 30 or 35 miles between Lost Nation and Preston in an hour and 20 minutes. An account in the Maquoketa Excelsior newspaper noted that a freight train easily ran ahead of the storm. This slow forward motion allowed warning to be sent from communities grazed by the tornado to those further along its path and many took shelter as a result. An observer near Stanwood reported hailstones to the size of walnuts falling from the storm with “much larger stones two miles northwest of here” while on the steam boat Saturn, two miles south of Sabula on the Mississippi River, an observer wrote that hail fell on the deck “in great quantities, chunks being found as large as a man’s fist” and that “the barrels on deck were filled with the ice.” At Preston hailstones were measured as large as 14 inches in circumference.

1892: Several weeks of wet weather took the Floyd River in Sioux City to bank full, then heavy rain on May 17th into the early morning of the 18th led to one of the worst flash floods in Sioux City history. The flood swept down the Floyd River between 6 and 7 am on the 18th, sending residents scrambling into trees or onto roofs. One observer wrote that “the first intimation was a volume of water spreading over the banks to a depth of three feet and throwing a mist of foam from it. In a few minutes the water had risen above the first floors and several thousand fled in terror to the higher ground. The water rose eight feet in one hour and a half and from nine o’clock continued to rise steadily but not so rapidly.” At its highest point it was reported that the river swept from the base of Floyd’s bluff to Court Street on its way into the Missouri River. The lumber yards, stock yards, and railroads were all severely damaged or destroyed and at least 2,000 head of livestock were drowned and seen floating down the river. Both electric plants were inundated, cutting power to the city for some time, and all business and transportation in the city were suspended. At least 25 people were drowned in the flood and several thousand were left homeless.

18 May 1898 → In Marathon County, WI, 30 miles of farms and forest were leveled by what was likely an F5 tornado. Seventeen people were killed, including 5 people from one family. The tornado was one of five violent twisters that hit the middle and upper Mississippi Valley during a two-day outbreak on May 17-18, 1898. At least 55 people were killed across the region. 18 May 1902 → 100 buildings were obliterated in Goliad, TX by an F4 (estimated) tornado. 114 people were killed. 18 May 1980 → Mount Saint Helens, WA, erupted, spewing ash and smoke nearly63,000 feet into the air. Heavy ash covered the ground as small particles were carried by the winds all the way to the Atlantic coast. 18 May 1995 → Near Ethridge, TN 6 TVA high-tension electric transmission towers were destroyed by an F4 tornado and were never found. Northern Alabama was hard hit as well, especially in the Anderson Hills area near Huntsville. Anderson Hills would be hit hard again during the April 27, 2011 tornado outbreak.

Posted under Weather History

From NWS
1996: A severe thunderstorm produced very large hail up to 4.5 inches in diameter at Charles City. A woman was injured by flying glass in her home.

1902: Slow moving thunderstorms produced very heavy rainfall and flash flooding across portions of far northeastern Iowa. Observers in Fayette and Postville measured more than 5 inches of rainfall in just a few hours. At McGregor the storm was accompanied by a terrific display of lightning which struck several buildings downtown including a saloon and billiard hall that was demolished. Flood waters flowed through most of the town, sewers backed up, and there was considerable damage to most structures in the area. Four people were injured in McGregor.

1877: Large hail fell at Hamlin in Audubon County where stones 6 inches in circumference smashed windows and crops, stripped the bark from trees, and killed many small animals.

17 May 1896 → A 2-mile wide path of utter destruction, made up of a nearly mile-wide F5 tornado plus powerful downburst winds, swept for 100 miles across northeast Kansas and the southeast corner of Nebraska. Seneca, KS was particularly hard hit and lost its opera house. Twenty-five people were killed. 17 May 1979 → It does get cold in Hawaii! The state’s record low was set on Mauna Kea, bottoming out at a rather chilly 12 degrees. 17 May 1983 → A golfer playing the Fox Meadows course in Memphis, TN was struck by a bolt of lightning that went through his neck, down his spine, came out a pocket containing his keys, and went into a nearby tree. He survived.

Posted under Weather History

From NWS
1999: A severe weather outbreak produced 13 tornadoes across Iowa including an F3 that killed 2 people and injured 16 near Logan. Slowly moving storms also produced very heavy rain in northeastern Iowa from the 16th into the 17th with overnight rainfall totals as high as 6.20 inches at Fayette and 5.53 inches at Tripoli. With the ground already nearly saturated the heavy rain led to record flooding on the Turkey River at Garber and the Wapsipinicon River at Independence. Severe flooding also occurred along the Volga River from Volga to Elkport. Many roads were flooded, bridges were swept away, and major damage occurred in Fayette, Oelwein, and several other communities. It was reported that at one point most of the town of Fayette was under several feet of water.

1997: A very unusual weather scenario resulted in Sioux City breaking both its record high and record low temperatures for the date with a morning low of 33 F and an afternoon high of 91 F.

1899: A tornado produced F4 damage along a track from near Greeley in Delaware County to northwest of Colesburg and into southern Clayton County. In one family near Greeley two people were killed and four others were severely injured. Another two people were killed and 10 more injured further along the path of the tornado in Clayton County.

1886: Several days of thunderstorms and scattered severe weather on May 12-14 were followed by an unseasonably strong cold front on the 15th. During the latter part of the day on the 15th light snow was observed mixed with rain in Clayton and Scott counties, and on the morning of the 16th a widespread frost covered nearly the entire state. An observer near Iowa City noted “white frost on fields. The sycamore maples in Iowa River Valley just north of town were frosted, some leaves turned brown.”

16 May 1874 → A flash flood caused by dam slippage claimed 143 lives and a million dollars in property damage at Mill Creek, west of Northhampton, MA. 16 May 1951 → Hurricane Able performed a loop north of the Bahamas and reached Category 3 strength off Cape Hatteras, NC. 16 May 2010 → A significant hail storm struck the Oklahoma City metro area with baseball sized hail. It was one of the most damaging and costly hail storms in Oklahoma history. The hail produced significant damage to automobiles, roofs, and vegetation and was accompanied by winds in excess of 50 MPH. Hail drifts several feet deep were reported, and some locations had hail still covering the ground 12 hours after it fell. Damage estimates exceeded $500 million.

Posted under Weather History

From NWS
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.

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.

15 May 1896 → An F5 (estimated) tornado struck the west side of Sherman, TX. There were 73 fatalities. A trunk lid was carried 35 miles. 15 May 1968 → A tornado touched down southwest of Anchorage, AK. It was one of just four tornadoes reported in Alaska since 1950. Also, a huge Midwestern tornado outbreakincluded two F5′s in Iowa resulting in 18 fatalities…most of them in Charles City.

Posted under Weather History

From NWS
1997: May was unusually cool across Iowa with many stations recording one of their coldest Mays on record. On the 13th-15th many areas of the state experienced freezing or near-freezing temperatures. The coldest temperatures in this stretch were reported across northern Iowa on the morning of the 14th including readings of 28 F at Fort Dodge and Northwood, 27 F at Le Mars and Waukon, and 24 F at Sibley. Late season flurries were also observed at some northeastern Iowa stations on the night of May 14-15 with traces of snowfall reported at Cresco, Decorah, Lansing, and Waukon.

14 May 1686 → Daniel Gabriel Fahrenheit, inventor of the mercury thermometer, was born. 14 May 1886 → At 10:00 pm, after having already caused one death in Indiana, an F4 tornado hit Celina, OH, leaving 5 more dead and 20 injured. Then at 11:30 pm, an F3 tornado killed 11 and injured 25 as it destroyed much of Dunkirk and Cary, OH. 14 May 1923 → Farms were swept off the earth by what was probably an F5 tornado south of Lubbock, TX. A man and his three sons were among the 23 fatalities. The damage path was up to a mile and a half wide. 14 May 1995 → At Grissom Air Force Base in Indiana, winds were recorded reaching 136 mph.

Posted under Weather History

From NWS
1918: A very late light snow was observed at a few locations in Iowa but it melted as it fell and generally did not accumulate. However, at Des Moines a light dusting occurred with 0.1 inches of snow reported making this the second-latest date of measurable snow on record at Des Moines, only two days earlier than the amazing statewide snowfall of May 15, 1907.

13 May 1930 → A man was killed when caught in an open field during a hailstorm northwest of Lubbock, TX. 13 May 1989 → Severe weather in the Southern Plains produced wind gusts up to 95 mph at Killeen, TX. At Fort Hood, 200 helicopters were damaged.

Posted under Weather History