Hurricane Mitch was the second-deadliest Atlantic hurricane on record, only after the Great Hurricane of 1780 which killed at least 22,000 people. Hurricane Mitch caused 11,374 fatalities in Central America in 1998, including approximately 7,000 in Honduras and 3,800 in Nicaragua due to cataclysmic flooding from the slow motion of the storm. It was the deadliest hurricane in Central American history, surpassing Hurricane Fifi–Orlene, which killed slightly fewer people there in 1974.
Hurricane Agnes in 1972 was the costliest hurricane to hit the United States at the time, causing an estimated $2.1 billion in damage. The hurricane's death toll was 128. The effects of Agnes were widespread, from the Caribbean to Canada, with much of the east coast of the United States affected. Damage was heaviest in Pennsylvania, where Agnes was the state's wettest tropical cyclone. Due to the significant effects, the name Agnes was retired in the spring of 1973.
The Johnstown Flood, sometimes referred to locally as Great Flood of 1889, occurred on Friday, May 31, 1889, after the catastrophic failure of the South Fork Dam, located on the south fork of the Little Conemaugh River, 14 miles (23 km) upstream of the town of Johnstown, Pennsylvania, United States. The dam ruptured after several days of extremely heavy rainfall, releasing 14.55 million cubic meters of water. With a volumetric flow rate that temporarily equaled the average flow rate of the Mississippi River, the flood killed 2,208 people and accounted for US$17,000,000 in damage.
Tropical Storm Amelia was a weak but catastrophic tropical storm that was the second-wettest tropical cyclone on record in the continental United States. Amelia developed from a tropical wave that moved through the Atlantic Ocean uneventfully. The disturbance then entered an area of the Gulf of Mexico that was conducive to tropical cyclogenesis and became the first tropical depression of the season, after which it was forecast to make landfall before any significant intensification. However, the tropical depression defied predictions, quickly strengthening into a weak tropical storm just hours before making landfall in Corpus Christi. The storm lasted roughly a day over land before becoming unidentifiable after being active for just under 48 hours. After dissipating, the storm caused a severe flooding disaster in Texas.
The Los Angeles flood of 1938 was one of the largest floods in the history of Los Angeles, Orange, and Riverside Counties in southern California. The flood was caused by two Pacific storms that swept across the Los Angeles Basin in February-March 1938 and generated almost one year's worth of precipitation in just a few days. Between 113–115 people were killed by the flooding. The Los Angeles, San Gabriel, and Santa Ana Rivers burst their banks, inundating much of the coastal plain, the San Fernando and San Gabriel Valleys, and the Inland Empire. Flood control structures spared parts of Los Angeles County from destruction, while Orange and Riverside Counties experienced more damage.
Floods in the United States are generally caused by excessive rainfall, excessive snowmelt, and dam failure. Below is a list of flood events that were of significant impact to the country during the 20th century, from 1900 through 1999, inclusive.
The 2009 Great Britain and Ireland floods were a weather event that affected parts of Great Britain and Ireland throughout November and into December 2009. November was the wettest month across the United Kingdom since records began in 1914 and had well above average temperatures. The worst affected area in Great Britain was the English county of Cumbria. The Irish counties of Clare, Cork, Galway and Westmeath were among the worst affected areas of Ireland.
The Great Flood of 1862 was the largest flood in the recorded history of California, Oregon, and Nevada, inundating the western United States and portions of British Columbia and Mexico. It was preceded by weeks of continuous rains and snows that began in Oregon in November 1861 and continued into January 1862. This was followed by a record amount of rain from January 9–12, and contributed to a flood that extended from the Columbia River southward in western Oregon, and through California to San Diego, and extended as far inland as Idaho in the Washington Territory, Nevada and Utah in the Utah Territory, and Arizona in the western New Mexico Territory. The event dumped an equivalent of 10 feet (3.0 m) of water in California, in the form of rain and snow, over a period of 43 days. Immense snowfalls in the mountains of far western North America caused more flooding in Idaho, Arizona, New Mexico, as well as in Baja California and Sonora, Mexico the following spring and summer, as the snow melted.
The Christmas flood of 1964 was a major flood in the United States' Pacific Northwest and some of Northern California between December 18, 1964, and January 7, 1965, spanning the Christmas holiday. Considered a 100-year flood, it was the worst flood in recorded history on nearly every major stream and river in coastal Northern California and one of the worst to affect the Willamette River in Oregon. It also affected parts of southwest Washington, Idaho, and Nevada. In Oregon, 17 or 18 people died as a result of the disaster, and it caused hundreds of millions of dollars in damage. The flooding on the Willamette covered 152,789 acres (61,831.5 ha). The National Weather Service rated the flood as the fifth most destructive weather event in Oregon in the 20th century. California Governor Pat Brown was quoted as saying that a flood of similar proportions could "happen only once in 1,000 years," and it was often referred to later as the Thousand Year Flood. The flood killed 19 people, heavily damaged or completely devastated at least 10 towns, destroyed all or portions of more than 20 major highway and county bridges, carried away millions of board feet of lumber and logs from mill sites, devastated thousands of acres of agricultural land, killed 4,000 head of livestock, and caused $100 million in damage in Humboldt County, California, alone.
The 2013 Colorado floods were a series of natural disasters occurring in the U.S. state of Colorado. Starting on September 11, 2013, a slow-moving cold front stalled over Colorado, clashing with warm humid monsoonal air from the south. This resulted in heavy rain and catastrophic flooding along Colorado's Front Range from Colorado Springs north to Fort Collins. The situation intensified on September 11 and 12. Boulder County was worst hit, with 9.08 inches (231 mm) recorded September 12 and up to 17 inches (430 mm) of rain recorded by September 15, which is comparable to Boulder County's average annual precipitation. This event has also been referred to as the 2013 Colorado Front Range Flood, reflecting a more precise geographic extent in and along the Colorado Front Range mountains.
The 1985 Election Day floods — also known as the Killer Floods of 1985 in West Virginia — produced the costliest floods in both West Virginia and Virginia in November 1985. The event occurred after Hurricane Juan, a tropical cyclone in the 1985 Atlantic hurricane season, meandered near the coast of Louisiana before striking just west of Pensacola, Florida late on October 31. Juan moved northward into Canada, but spawned another system that spread moderate rainfall across the Mid-Atlantic States, wetting soils. On November 3, a low pressure area developed south of Florida and moved northeastward along a cold front, bringing a plume of moisture influenced by Juan's previous track. The storm moved through the southeastern United States, stalling on November 5 west of Washington, D.C. before turning out to sea the next day. The event was known as the Election Day floods due to its concurrence with elections in Virginia.
The 2015–2016 Great Britain and Ireland floods were a series of heavy rainfall events which led to flooding during the winter of late 2015 and early 2016. 11 named storms produced record level rainfall from November 2015 - March 2016 in both monthly and seasonal accumulation records.
In June 2016, parts of the United Kingdom were struck by serious flash floods. Starting on 7 June, thunderstorms caused intense rainfall in many locations across the country, particularly in the north of England and in London, causing repeated flash floods in several locations on a daily basis.
The 1936 Northeastern United States flood was a historic flood that occurred across the Northeastern United States, as well as the Mid-Atlantic region and Ohio, in March 1936. Record-setting flooding after a combination of a particularly precipitation-heavy winter and large amounts of rainfall in March caused severe damage across the region.
Between November 2019 and February 2020, severe winter flooding occurred across the United Kingdom. The first wave of flooding occurred in November 2019, mainly affecting Yorkshire and the Humber, the East Midlands and the West Midlands. Further isolated flooding incidents were reported in December and January, before the second main wave of flooding, caused by Storms Ciara and Dennis, occurred in February 2020. The excessive rainfall resulted in the wettest February since records began, in 1766, in England and Wales with an average of 169.6 millimetres (6.68 in) falling across the regions, beating the record from 1833.
In July 2019, parts of the Yorkshire Dales, in North Yorkshire, England, were subjected to above average rainfall for the time of year. The flash-flooding that followed affected many communities destroying bridges, sweeping roads away, causing landslips on railway lines and resulting in at least one public event being cancelled. The flooding even inundated the fire station in the town of Leyburn, in Wensleydale, whilst the crew were out helping those in need. The recovery took many weeks and months, with immediate help by the rescue services being bolstered by British Army personnel who assisted with the clean up.
Hispaniola is an island in the Caribbean, with the second largest size throughout all of the Caribbean. Throughout the centuries, since reliable records began, hundreds of hurricanes and tropical cyclones have affected Haiti and the Dominican Republic, the two countries that share the island. The most recent tropical cyclone to affect Hispaniola was Hurricane Fiona in September 2022.
Extreme rainfall on the east coast of Australia beginning on 18 March 2021 led to widespread flooding in New South Wales, affecting regions from the North Coast to the Sydney metropolitan area in the south. Suburbs of Sydney experienced the worst flooding in 60 years, and the events were described by NSW Premier Gladys Berejiklian as "one in 100-year" flooding. Far-southeast communities in Queensland were also affected by flooding and heavy rainfall, though to a lesser extent than those in New South Wales.
Between midnight and 10:00 am CDT on Saturday, August 21, 2021, very heavy rainfall resulted in widespread flash flooding across western Middle Tennessee, including the town of Waverly. During the event, much of a five-county area received up to a quarter of normal annual rainfall in under twelve hours, as much as 10 to 15 inches. In a situation described as catastrophic, Waverly was severely damaged by floodwater, with hundreds of homes and dozens of businesses destroyed and swept away. Numerous people became trapped, leading to widespread water rescues. The event resulted in 19 fatalities in Waverly, with another in nearby Hurricane Mills, and is regarded as one of the worst natural disasters in Tennessee history. The event broke the 24-hour rainfall record in Tennessee, with over 20 inches (510 mm) of rain falling in McEwen. Flooding also occurred in parts of western Kentucky, but to a much lesser extent.
