The Worst Natural Disasters in US History, Ranked
The deadliest natural disaster in US history was the 1900 Galveston hurricane, which killed roughly 8,000 people. The costliest was Hurricane Katrina, at about $201 billion. Here's the strange part: those are almost two entirely different lists — and the reason why is a century of forecasting, building codes and coastal wealth.
Ask what the “worst” natural disaster in American history was and you get two right answers, because there are two ways to keep score. One list ranks disasters by the number of people they killed. The other ranks them by the dollars of damage they did. Line the two lists up side by side and they barely share an entry.
That divergence isn't random. It's the clearest single illustration of how the relationship between Americans and extreme weather has changed. Below, both rankings, then the explanation for why they look so different.
Deadliest Natural Disasters in US History
Ranked by estimated lives lost, weather and geophysical events only. Notice how far back you have to look: the top of this list is dominated by disasters from before modern forecasting and organized evacuation existed.
| Disaster | Year | Type | Deaths | What happened |
|---|---|---|---|---|
| Galveston Hurricane | 1900 | Hurricane | ~6,000–12,000 | A Category 4 struck Galveston, Texas, with no effective warning and no seawall. It killed roughly one in six residents and remains, by a wide margin, the deadliest natural disaster in US history. ~8,000 is the standard estimate. |
| San Francisco Earthquake & Fire | 1906 | Earthquake | 3,000+ | The magnitude-7.9 quake and the three days of fire that followed destroyed most of the city — the deadliest earthquake in US history. |
| Hurricane Maria | 2017 | Hurricane | ~2,975 | A Category 4 devastated Puerto Rico and knocked out power for months. Most deaths were indirect, from the prolonged loss of power, water and medical care — the deadliest US disaster in a century. |
| Okeechobee Hurricane | 1928 | Hurricane | ~2,500+ | Lake Okeechobee overtopped its dike and drowned farming communities across South Florida. The toll is often given as 2,500–4,000; most victims were never identified. |
| Johnstown Flood | 1889 | Flood (dam failure) | 2,209 | The South Fork Dam failed after heavy rain, sending 20 million tons of water into Johnstown, Pennsylvania, in minutes — the benchmark American flood disaster. |
| Chenière Caminada Hurricane | 1893 | Hurricane | ~2,000 | A Category 4 obliterated a barrier-island fishing village in Louisiana. One of two catastrophic 1893 Gulf/Atlantic hurricanes that year. |
| Peshtigo Fire | 1871 | Wildfire | ~1,500–2,500 | The deadliest wildfire in US history swept through northeast Wisconsin the same night as the Great Chicago Fire, which it far outstripped in lives lost. |
| Hurricane Katrina | 2005 | Hurricane | 1,392 | The failure of the New Orleans levee system flooded 80% of the city. The deadliest US hurricane in seven decades — and, separately, the costliest disaster of any kind. |
| Labor Day Hurricane | 1935 | Hurricane | 408 | The most intense hurricane ever to hit the US at landfall (Category 5, 892 mb) struck the Florida Keys and killed hundreds of World War I veterans working there. |
| Great Mississippi Flood | 1927 | Flood | ~250–500 | The most destructive river flood in US history inundated 27,000 square miles across the Mississippi Valley and displaced hundreds of thousands. |
This ranking excludes epidemics (the 1918 flu killed roughly 675,000 Americans) and man-made disasters, to keep it to natural weather and geophysical events. Older death tolls are estimates and ranges; Maria's ~2,975 figure is the excess-death estimate adopted by Puerto Rico. For depth on any single hazard, see our deadliest hurricanes, worst floods and deadliest tornadoes lists.
Costliest Natural Disasters in US History
Ranked by total damage, CPI-adjusted to 2024, from NOAA's Billion-Dollar Weather and Climate Disasters dataset. Notice the opposite pattern: every event on this list is from the 21st century except Andrew (1992) — and all nine are hurricanes.
| Disaster | Year | Type | Cost (2024 $) | Notable |
|---|---|---|---|---|
| Hurricane Katrina | 2005 | Hurricane | $201.3B | The costliest disaster in US history, driven by catastrophic levee failure and flooding in New Orleans. |
| Hurricane Harvey | 2017 | Hurricane | $160.0B | Stalled over Texas and dropped over 60 inches of rain — the wettest tropical cyclone in US history. |
| Hurricane Ian | 2022 | Hurricane | $119.6B | A Category 4 that devastated southwest Florida with a record surge around Fort Myers. |
| Hurricane Maria | 2017 | Hurricane | $115.2B | The Puerto Rico catastrophe — costly and deadly, one of the few storms on both of these lists. |
| Hurricane Sandy | 2012 | Hurricane | $88.5B | A 1,000-mile-wide late-October storm that flooded New York City and the Northeast coast. |
| Hurricane Ida | 2021 | Hurricane | $84.6B | Came ashore in Louisiana as a Category 4, then caused deadly flash flooding as far north as New York. |
| Hurricane Helene | 2024 | Hurricane | $78.7B | Made a Big Bend Florida landfall, then caused historic inland flooding across the southern Appalachians. |
| Hurricane Irma | 2017 | Hurricane | $64.0B | One of three 2017 hurricanes on this list — the costliest US hurricane season on record. |
| Hurricane Andrew | 1992 | Hurricane | $60.5B | The Category 5 that leveled Homestead, Florida, and rewrote the state’s building codes. |
Figures are NCEI totals, CPI-adjusted to 2024. Since 1980, the US has sustained more than 400 separate billion-dollar weather and climate disasters totaling over $2.9 trillion, and tropical cyclones account for more than half of that — over $1.5 trillion.
Why the Two Lists Barely Overlap
Only one storm — Hurricane Maria in 2017, and to a lesser degree Katrina — appears near the top of both rankings. Everything else lands on one list or the other. That split tells a story about a hundred years of American progress and American choices.
The deadliest disasters are old because forecasting and evacuation didn't exist yet. In 1900, Galveston had no satellite, no hurricane warning, no seawall — the storm arrived essentially unannounced, and 8,000 people had nowhere to go. Johnstown had no way to know a dam was about to fail. Today, the National Hurricane Center tracks a storm for a week and coastal counties evacuate hundreds of thousands of people before landfall. That single change has cut the death toll of a major hurricane by a factor of ten to a hundred.
The costliest disasters are new for the opposite reason: we keep building more, and more expensively, in harm's way. The Florida coast that Andrew and Ian struck holds vastly more — and more valuable — property than it did a lifetime ago. So even as we save far more lives, we lose far more money. A storm no deadlier than one from 1950 now does ten times the dollar damage, simply because there is ten times as much to destroy where it lands. The two lists aren't contradictory. They're two sides of the same century.
Go Deeper by Hazard
This page ranks the single worst events across every hazard type. For the full ranked history of each one, we keep dedicated lists: the deadliest hurricanes, the worst floods, the deadliest tornadoes, the worst heat waves, the worst wildfires, the worst winters, and the worst ice storms. To see which states face the most hazards at once, read the states hit by tornadoes, hurricanes and wildfires.
Frequently Asked Questions
What was the worst natural disaster in US history?
It depends on how you measure it. By death toll, the 1900 Galveston hurricane is the worst, killing an estimated 6,000 to 12,000 people in Texas. By cost, Hurricane Katrina (2005) is the worst, with $201 billion in inflation-adjusted damage. The two rankings are almost entirely different lists.
What was the deadliest natural disaster in US history?
The Galveston Hurricane of September 8, 1900. The Category 4 storm struck Galveston, Texas, with little warning and no seawall, killing roughly 8,000 people — about one in six residents. No US natural disaster before or since has killed as many.
What was the costliest natural disaster in US history?
Hurricane Katrina in 2005, at roughly $201 billion in CPI-adjusted damage per NOAA NCEI. The failure of the New Orleans levee system flooded 80% of the city. Hurricane Harvey (2017, ~$160 billion) is second. Tropical cyclones account for the large majority of America’s costliest disasters.
Why are the deadliest disasters so different from the costliest?
The deadliest disasters are mostly old (Galveston 1900, Johnstown 1889, Okeechobee 1928) because they struck before modern forecasting and evacuation. The costliest are almost all recent (Katrina, Harvey, Ian) because far more people and far more expensive property now sit in harm’s way. Forecasting cut death tolls; coastal development multiplied damage.
Sources & Method
The deadliest ranking uses estimated lives lost for natural weather and geophysical disasters (epidemics and man-made events excluded), with tolls from the National Hurricane Center, NWS, USGS and the Wikipedia List of disasters in the United States by death toll, which aggregates the primary agency reports. Costs are from NOAA's Billion-Dollar Weather and Climate Disasters dataset, CPI-adjusted to 2024 (accessed September 24, 2026). This site has no cross-disaster database, so no figure here is computed — each traces to the agency record cited, and per-hazard depth links to our own dedicated pages.