Notable global weather events that occurred on September 9 include several powerful hurricanes and significant flooding.

1775:

The “Independence Hurricane” of 1775 was not a single storm that struck Halifax, but rather a system that affected the Atlantic coast of the American colonies before delivering its most catastrophic blow to Newfoundland. The storm, also known as the Great Newfoundland Hurricane, killed an estimated 4,000 to 4,163 people, most of them sailors at sea off Newfoundland, making it Canada’s deadliest natural disaster.

Path and timeline

Formation (late August): The storm originated near the Outer Banks of North Carolina, making landfall on August 27, 1775. It caused significant damage and killed over 100 people in North Carolina and Virginia before moving northeast.

Coastal impact (early September): As the storm tracked up the coast, it affected ports and towns from Virginia to New England. In Virginia, it drove the British naval vessel HMS Otter ashore, where it was destroyed by American rebels. Colonial ports like Norfolk, Hampton, and Yorktown also suffered damage.

Arrival in Newfoundland (September 9): The main devastation occurred when the hurricane struck Newfoundland on September 9, which was the peak of the fishing season. There is historical debate whether this was the same storm that hit the colonies or a separate one, but its effect on the island was devastating.

Devastation in Newfoundland

Storm surge: The storm produced a massive storm surge, with ocean levels rising an estimated 20 to 30 feet. This wall of water overwhelmed coastal settlements and fishing premises.

Maritime catastrophe: The vast majority of the 4,000+ fatalities were sailors and fishermen caught on the Grand Banks and other fishing grounds.

Over 700 boats were reportedly lost, including 300 in Harbour Grace alone.

Two Royal Navy schooners patrolling the fishing grounds to enforce British rights were also wrecked.

Catastrophic loss of life: Given that the summertime population of Newfoundland was estimated at 8,000 to 10,000 people, the death toll represented a staggering proportion of the island’s temporary inhabitants. Many of the deceased were fishermen from England and Ireland.

Onshore destruction: The storm wiped out the entire fishing industry, destroying warehouses, fishing stages, and provisions of oil and salt fish. It was reported that for days and weeks after the hurricane, fishing nets were pulling in human bodies.

Forgotten disaster: Despite its severity, the hurricane was largely forgotten for decades. Its memory was obscured by the ongoing Revolutionary War, and it was misattributed as a tidal wave or earthquake in some early accounts.

Connection to the American Revolution

The name “Independence Hurricane” was coined later because the storm occurred during the early months of the American War of Independence. American colonists reportedly viewed the catastrophe, which decimated a crucial British economic sector, as a sign that their cause was just and sanctioned by God. However, historical sources confirm that the hurricane did not have a direct or decisive impact on the outcome of the war.

1821: The New England tornado outbreak of September 9, 1821, produced at least five confirmed tornadoes, including the deadliest single tornado in New Hampshire’s history. Historical accounts from diaries and local newspapers describe widespread destruction across Vermont, New Hampshire, and Massachusetts.

New Hampshire’s deadliest tornado

The most devastating storm of the outbreak touched down in New Hampshire and may have originated in Vermont.

Path and multiple vortices: The tornado carved a path up to half a mile wide and, according to eyewitness accounts, displayed a multiple-vortex structure.

Lake Sunapee: The funnel cloud crossed the lake, and witnesses reported seeing it churn up water from the surface. A stone wall along the shore was toppled, with some stones weighing 70 pounds thrown a distance of four feet. Items torn from homes, including furniture, were carried for two miles across the lake.

Fatalities: Six of the outbreak’s eight total fatalities occurred in New Hampshire.

In the town of Wendell (now Sunapee), a baby’s bed was found on the far side of Lake Sunapee, while the child’s body was recovered later from the lake shore.

In the settlement of Kearsarge Grove near Warner, all seven homes were completely destroyed.

Fierce power: The tornado was estimated to be an F4 on the Fujita scale, with winds over 200 mph. The destruction it caused was so extreme that one account noted, “any homes in its path weren’t just swept away; they were shattered into small fragments and splinters”.

Visibility of damage: The path of destruction through the forests of towns like Cornish was so severe that it was visible for decades after the event.

Tornadoes in Massachusetts

Another powerful tornado swept through parts of Massachusetts, resulting in two additional deaths and numerous injuries.

Impact on Warwick: In the southern part of Warwick, buildings were completely leveled. Wreckage, including clothing, boards, and parts of a barn roof, was reportedly carried as far as 30 miles away.

Casualties: In addition to the two fatalities, 17 people were injured.

Vermont’s tornadic storms

Multiple tornadoes: One of the confirmed storms started in Washington County, Vermont, near Berlin, where it caused tree damage.

Pittsford and Hubbardton: Another potential tornado struck parts of Vermont, damaging buildings in Pittsford and Hubbardton. A book from a Pittsford home was carried an incredible six miles.

Lake Champlain origin theory: One historical claim suggests the New Hampshire and Massachusetts tornadoes were branches of a single, larger tornado that originated at Lake Champlain.

Broader context of the outbreak

Limited damage: While the storms were exceptionally powerful and destructive in their immediate paths, the overall damage and low death toll (for such powerful storms) was attributed to the fact that the tornadoes passed mainly through uninhabited areas.

A historical record: The outbreak and subsequent detailed documentation of its effects make it one of the most severe tornado events in early New England history. The observations from this event provide a valuable historical record of tornado behavior and destruction.

1931: The September 9–12, 1931 heatwave in the Upper Midwest was an unusually intense event for so late in the season, during what was already the warmest September on record. Occurring during the prolonged drought of the early 1930s, this dry heat was a precursor to the devastating Dust Bowl era.

Meteorological conditions

A strong ridge of high pressure was situated over the western U.S., which funneled the heat northward into the Upper Midwest and Great Lakes region.

Existing drought conditions, which began in the winter of 1930–1931, meant that the land was already parched. With no soil moisture to evaporate, the sun’s energy was used exclusively to heat the ground, causing temperatures to soar higher than they would have otherwise.

Temperature records

Many long-standing heat records were set across South Dakota and Minnesota from September 9–12, 1931, with temperatures hitting up to 10 degrees above normal for the month.

South Dakota:

Kennebec: Hit 109°F on September 9.

Aberdeen: Reached 107°F on September 10.

Mobridge: Saw a high of 105°F on September 9.

Timber Lake: Hit 106°F on September 9.

Watertown: Reached 104°F on September 10.

Minnesota:

Beardsley: Reached 111°F.

Wheaton: Hit 108°F on September 10.

Morris, New Ulm, and Canby: All recorded a high of 106°F.

Milan: Hit 108°F.

Minnesota State Fair: Reached 104°F.

Impact on the region

Agricultural distress: The extreme heat exacerbated the existing drought, leading to crop failures, livestock losses, and widespread economic distress among farmers. The agricultural disaster contributed to the widespread famine and malnutrition that swept through many communities during this period.

Soil erosion: The combination of heat and drought destroyed ground cover, which resulted in a surge of wind erosion across the Great Plains and marked a prelude to the devastating dust storms of the Dust Bowl.

Water shortages: With rivers, wells, and springs drying up, many people were forced to use untreated water, increasing the risk of diseases like typhoid. Shrinking water supplies also became a public health challenge for urban areas.

Health crisis: The heat resulted in cases of heatstroke and heat exhaustion. While more lethal heatwaves occurred earlier in 1931 and throughout the decade, people in urban centers suffered without modern air conditioning. For relief, some cities opened public parks or saw record crowds at nearby beaches.

Broader context of the 1930s

The September 1931 event was one of several extreme heatwaves during the 1930s, which became the hottest decade on record at the time. Poor land management practices—like over-plowing—combined with natural drought cycles intensified these hot patterns and contributed to the Dust Bowl, a human and environmental disaster.

1942: On September 9, 1942, Japanese pilot Nobuo Fujita launched from the submarine I-25 and dropped incendiary bombs over the forested area near Brookings, Oregon, in an attempt to start large wildfires and cause strategic damage to the U.S. mainland. Although Fujita succeeded in starting a small fire, damp conditions in the forest prevented it from spreading significantly. This event, followed by a second failed attempt on September 29, marked the only aerial attack on the U.S. mainland during World War II, a retaliatory operation for the American Doolittle Raid on Tokyo. Decades later, in a remarkable story of reconciliation, Fujita returned to Brookings in 1962, bringing his samurai sword as a gesture of peace, planting redwood trees, and forging a deep friendship with the townspeople, who later named him an honorary citizen. 

Details of the Attack

Date and Location:

The first attack occurred on September 9, 1942, in a forested area near Brookings, Oregon.

The Aircraft and Submarine:

Fujita flew a Yokosuka E14Y “Glen” seaplane, a lightweight floatplane launched from the Japanese submarine I-25.

The Objective:

The goal was to ignite massive forest fires to divert U.S. military resources, a strategy also used by Japan in the Doolittle Raid.

Outcome:

The incendiary bombs, however, failed to cause significant damage due to the unusually wet conditions of the forest, which quickly contained the fires.

The Second Attack and Its Aftermath

Second Bombing: A second bombing attempt was made on September 29, 1942.

Minimal Impact: Again, the attack had little effect, with no significant fires or damage resulting from the second raid.

Secrecy: Information about these attacks was not released to the public until the following year, contributing to the general lack of widespread panic on the U.S. West Coast.

A Story of Reconciliation

Fujita’s Return:

In 1962, Fujita returned to Brookings as an envoy of peace and reconciliation.

The Sword of Peace:

He presented his family’s 400-year-old samurai sword, carried during the bombing mission, to the town as a symbol of his regret and a hope for friendship between former adversaries.

Enduring Friendship:

Fujita’s efforts led to a deep and lasting relationship with the town, including planting redwood trees as symbols of peace and sponsoring student exchanges between the U.S. and Japan.

Honorary Citizen:

He was named an honorary citizen of Brookings and is remembered for transforming an act of war into a story of forgiveness and understanding. His sword is now displayed at the Brookings Public Library.

1965:  Hurricane Betsy made landfall as a powerful Category 4 storm in Louisiana in September 1965, becoming the first hurricane in U.S. history to cause over $1 billion in damage. Nicknamed “Billion Dollar Betsy,” the storm caused immense flooding in New Orleans after breaching levees and is remembered as one of the most destructive hurricanes of its time.

The path of Hurricane Betsy

Formation and early path: Betsy formed as a tropical wave southwest of Cape Verde on August 23, 1965. After slowing and stalling for several days, it strengthened into a hurricane and struck the Bahamas as a Category 3 storm in early September.

Impact on Florida: The storm then moved along the coast of South Florida, making landfall near Key Largo as a Category 3 hurricane on September 8. In Florida, Betsy caused extensive flooding and killed five people. Total damages in the state were estimated at $139 million.

Strengthening in the Gulf: Betsy’s rapid movement and intensifying strength in the warm waters of the Gulf of Mexico were considered anomalous at the time. It regained Category 4 intensity as it approached the Central Gulf Coast.

Louisiana landfall: The hurricane made its second and most devastating landfall near Grand Isle, Louisiana, around 10 p.m. on September 9. The storm’s large eye and powerful winds, estimated to have reached up to 160 mph in gusts, caused catastrophic damage.

Path inland: After landfall, Betsy moved inland, maintaining hurricane strength as far north as Baton Rouge before weakening to a tropical storm. Its remnants eventually dissipated over the Ohio River Valley.

Major impacts in New Orleans and Louisiana

Catastrophic flooding: Betsy’s strong storm surge pushed a 10-foot wall of water into Lake Pontchartrain and the Mississippi River Gulf Outlet (MRGO). This overwhelmed and breached levees along the Industrial Canal and in the Lower Ninth Ward, flooding large sections of New Orleans.

Widespread damage: Approximately 164,000 homes in New Orleans were flooded, particularly in the Lower Ninth Ward, St. Bernard Parish, and Gentilly. Floodwaters did not fully recede for up to 10 days in some areas.

Power and infrastructure loss: Winds exceeding 100 mph knocked out 90% of New Orleans’ electrical grid, crippling the city’s pumping system. Telecommunication services were also widely disrupted.

Offshore damage: Offshore oil platforms in the Gulf were destroyed, and a barge carrying 600 tons of chlorine gas sank near Baton Rouge, prompting an evacuation. The barge was recovered months later.

Agricultural devastation: Sugarcane, cotton, and pecan crops were destroyed, and thousands of livestock drowned across Louisiana.

Legacy and aftermath

Financial toll: The total damage estimate was $1.42 billion in 1965, a figure that is equivalent to roughly $12 billion today.

Death toll: The storm was responsible for 81 fatalities, primarily in Louisiana.

Federal response: President Lyndon B. Johnson quickly visited the area and promised federal aid. The widespread destruction led Congress to order the U.S. Army Corps of Engineers to create the Hurricane Protection Program, building stronger levees for New Orleans.

Lessons for Katrina: The new levees were built to withstand a fast-moving Category 3 hurricane like Betsy. However, they failed when faced with the more powerful and slow-moving Hurricane Katrina in 2005, which struck the region nearly 40 years later.

Storm name retired: Due to the severe damage and loss of life, the name “Betsy” was retired from the rotating list of Atlantic hurricane names.

1994:  The Glasgow, Montana, heat burst of 1994 was a rare and short-lived meteorological event characterized by a rapid, intense temperature spike accompanied by a sharp decrease in humidity. This sudden rise in temperature was caused by a specific atmospheric process associated with a dying thunderstorm.

Timeline of the Glasgow heat burst

When it happened: The event was an overnight phenomenon, occurring in the late spring or summer of 1994, which is typical for heat bursts.

Temperature shift: The temperature in Glasgow climbed dramatically from 67°F to 97°F in just 15 minutes. This dramatic and sudden rise is a hallmark of a heat burst.

Other effects: In addition to the flash heating, a heat burst also features a rapid drop in dew point (humidity) and strong, gusty winds.

The mechanics of a heat burst

A heat burst is a dry variation of a downburst, and it requires a specific set of atmospheric conditions to occur.

A decaying thunderstorm: The process begins with a thunderstorm that is losing its energy source (the updraft). As the storm dies, it becomes dominated by a downdraft of air.

Dry mid-levels: For a heat burst to occur, the atmosphere in the middle altitudes must be hot and extremely dry.

Evaporation and acceleration: As the downdraft of air and precipitation descends through this dry air layer, all of the rain evaporates before it can reach the ground, a phenomenon known as virga. The evaporation initially cools the air, making it denser and accelerating its descent.

Compressional heating: After all the moisture is gone, the air continues to plunge toward the surface. As air sinks, it is compressed by the increasing atmospheric pressure, which causes it to heat up rapidly.

Reaching the surface: The hot, dry air pocket, still descending with momentum, eventually hits the ground and spreads out. This creates a rapid, localized temperature spike and gusty winds, which is the heat burst felt at the surface.

Significance and rarity

Rare phenomenon: Heat bursts are relatively rare because they require the exact combination of a decaying thunderstorm and a hot, dry mid-level atmosphere.

Localized and short-lived: These events are also highly localized and brief, with the intense heat and wind only lasting for a few minutes to an hour before temperatures return to normal.

Potential for damage: While most are harmless, the strongest heat bursts can produce damaging winds that can knock down trees and power lines. The most extreme historical events have been known to scorch crops.

2013: The 2013 Colorado Front Range flood began with intense, multi-day rainfall from September 9-16, causing catastrophic flash flooding and landslides along the Front Range and subsequent river flooding on the South Platte River. The event resulted in at least 9 fatalities, the destruction of over 2,000 homes and 200 businesses, and widespread damage to infrastructure across 18 counties, leading to a total economic impact of around $4 billion (in 2023 dollars). 

Meteorological Conditions

Heavy Rainfall:

The floods were caused by a slow-moving, stationary area of heavy rain along the Front Range, resulting from a weak weather disturbance.

Atmospheric Setup:

The event was characterized by multiple meteorological ingredients that set the stage for heavy precipitation and flash flooding along the Front Range.

Duration and Extent:

Historic rainfall lasted from September 9 to September 16, with the heaviest rainfall occurring on September 11-12.

Impact and Consequences

Fatalities: At least nine people died as a result of the flooding.

Evacuations and Rescues: More than 19,000 people were evacuated and 1,750 individuals were rescued.

Property Damage: Thousands of homes and businesses were destroyed or damaged, affecting over 26,000 damaged homes.

Infrastructure Damage: Over 200 miles of roads and 50 major bridges were damaged or destroyed.

Landslides: The heavy rainfall also triggered more than 1,100 landslides, creating dangerous debris flows.

Geographic Scope: The floods impacted 18 counties across more than 4,500 square miles, from Colorado Springs to Fort Collins and down the South Platte River.

Economic Impact

Damage Costs: The total estimated cost of the disaster was approximately $4 billion, when adjusted to 2023 dollars.

Response and Assessment

FEMA Declarations: The flooding led to FEMA disaster declarations for 15 counties.

National Weather Service Analysis: A NOAA service assessment noted that while models showed heavy rain, the precise timing, magnitude, and extent of the extreme event were difficult to predict accurately.

2017: The event you’re likely referring to occurred on September 9, 2017, not 2017 in general, when a strong thunderstorm caused flash flooding in Palm Springs and Cathedral City, California. This powerful storm resulted in waist-high flooding in some areas, caused power outages for thousands, damaged property including homes in Cathedral City, and stranded vehicles in floodwaters. 

Impacts of the September 9, 2017, Storm

Record Rainfall and Flooding:

The storm produced heavy rainfall, breaking rain records for the day in Palm Springs, with some areas experiencing even greater downpours and waist-high flooding.

Infrastructure Damage:

Streets and washes in Palm Springs and Cathedral City were inundated, with roads like Cathedral Canyon Drive becoming impassable.

Power Outages:

Thousands of customers across Southern California experienced power outages due to downed trees and utility lines.

Stranded Vehicles:

Water swept up and flooded vehicles, leading to rescues on Golf Club Drive in Palm Springs.

Property Damage:

Homes, including those at Canyon Mobile Home park in the Coachella Valley, suffered flood damage.

Specific Details:

Date: September 9, 2017

Location: Palm Springs, Cathedral City, and the wider Coachella Valley

Cause: A powerful thunderstorm with heavy rain

Consequences: Widespread flash flooding, power outages, stranded vehicles, and property damage

Note: While 2017 saw widespread flooding across California, particularly during winter storms, the specific event featuring flash flooding in Palm Springs and Cathedral City with property damage and power outages happened in September of that year.

2023: The severe flash flooding on September 9, 2023, in northeastern Pennsylvania’s Clarks Summit area, caused by intense rainfall from severe storms, resulted in the deaths of two people and widespread damage, including flooded homes, a collapsed bridge, and flooded roadways. The storms dropped over four inches of rain in under seven hours, overwhelming local infrastructure and leading to significant disruptions, such as flooded homes, damaged schools, and stranded vehicles.

Details of the Event

Date and Time:

The severe storms and flash flooding occurred on Saturday, September 9, 2023.

Rainfall:

The event dropped more than four inches of rain in less than seven hours.

Location:

The hardest-hit area was Clarks Summit, in Lackawanna County, Pennsylvania.

Cause:

Severe storms produced heavy rainfall, which triggered widespread flash flooding.

Impact and Consequences

Fatalities: The flash flooding caused the deaths of two people.

Damage:

Homes and roads were flooded, with one section of Bailey Street over Leggetts Creek destroyed.

A bridge on Falls Road in Newton Township collapsed.

Three school buildings in the Abington Heights School District were damaged.

Disruptions:

The storm overwhelmed local flood control systems.

Vehicles were stranded on highways due to the flooding.

Rescue Efforts: Water rescues were conducted, especially in the Clarks Summit area.

Contributing Factors

The rapid and intense amount of rainfall overwhelmed the area’s existing infrastructure and flood systems.

Severe storms with a constant feed of moisture contributed to the organized and prolonged storm development in the region.