PlainHazard

Landslides and avalanches in the United States, by state

The national record since 1996 · Debris Flow, Avalanche

NOAA's Storm Events Database records 3,416 landslide and avalanche records in the United States from 1996 through June 30, 2026, about 126 a year since 2000. California records the most (823), Puerto Rico the most per square mile. The deadliest storm in NOAA's record since 1996 is the March 22, 2014 debris flow in Washington: 43 deaths, 12 injuries and $74.8 million in damage in 2025 dollars.

Landslides and avalanches, 1996 to 2026

Records per year (NOAA Storm Events); 2026 to June 30, 2026.

  • recorded, no damage figure
  • under $10 million
  • $10 million or more
  • $100 million or more
  • $1 billion or more, or 100 deaths
  • $10 billion or more, or 1,000 deaths
  • a year's colour: its recorded damage or deaths
  • a year with a death
Records
3,4161996 to June 30, 2026
A year since 2000
126average
Deaths
616recorded
Damage, 2025 dollars
$1.7BStorm Events, as filed

Source: NOAA NCEI Storm Events Database, records through June 30, 2026; damage in 2025 dollars. Search the record at NCEI.

Which states have the most landslide and avalanche records?

By count California (823), Puerto Rico (629), Colorado (576) lead. Per 10,000 square miles Puerto Rico (1837), Colorado (56), California (53) lead; large states collect more records by covering more ground.

By count since 1996

  1. California 823
  2. Puerto Rico 629
  3. Colorado 576
  4. Washington 254
  5. Utah 191
  6. Idaho 167
  7. Alaska 102
  8. Wyoming 98
  9. Oregon 91
  10. Montana 76
  11. North Carolina 64
  12. Kentucky 60
  13. Nevada 59
  14. Arizona 41
  15. Virginia 34

Per 10,000 square miles

  1. Puerto Rico 1837
  2. Colorado 56
  3. California 53
  4. Hawaii 39
  5. Washington 38
  6. Utah 23
  7. Idaho 20
  8. Kentucky 15
  9. North Carolina 13
  10. Wyoming 10
  11. Oregon 9.5
  12. West Virginia 9.2
  13. Virginia 8.6
  14. New Hampshire 6.7
  15. Nevada 5.4

Source: Land area: Census Bureau 2024 Gazetteer; places under 1,000 square miles are not ranked per square mile.

Alabama: 1.2 per 10,000 sq miAlaska: 1.8 per 10,000 sq miArizona: 3.6 per 10,000 sq miArkansas: 0.6 per 10,000 sq miCalifornia: 53 per 10,000 sq miColorado: 56 per 10,000 sq miFlorida: 0.2 per 10,000 sq miGeorgia: 1.0 per 10,000 sq miHawaii: 39 per 10,000 sq miIdaho: 20 per 10,000 sq miIllinois: 0.4 per 10,000 sq miKentucky: 15 per 10,000 sq miMaine: 0.6 per 10,000 sq miMassachusetts: 3.8 per 10,000 sq miMinnesota: 0.1 per 10,000 sq miMississippi: 0.2 per 10,000 sq miMontana: 5.2 per 10,000 sq miNebraska: 0.1 per 10,000 sq miNevada: 5.4 per 10,000 sq miNew Hampshire: 6.7 per 10,000 sq miNew Mexico: 2.2 per 10,000 sq miNew York: 2.5 per 10,000 sq miNorth Carolina: 13 per 10,000 sq miOhio: 0.7 per 10,000 sq miOregon: 9.5 per 10,000 sq miPennsylvania: 1.8 per 10,000 sq miSouth Carolina: 0.3 per 10,000 sq miTennessee: 2.2 per 10,000 sq miTexas: 0.1 per 10,000 sq miUtah: 23 per 10,000 sq miVermont: 1.1 per 10,000 sq miVirginia: 8.6 per 10,000 sq miWashington: 38 per 10,000 sq miWest Virginia: 9.2 per 10,000 sq miWisconsin: 0.2 per 10,000 sq miWyoming: 10 per 10,000 sq mi
  • 0.1-0.4
  • 0.4-1.8
  • 1.8-5.4
  • 5.4-15
  • 15+
Landslides and avalanches per 10,000 square miles by state since 1996. Each class holds about a fifth of the states; Alaska and Hawaii are drawn as insets, not to scale.

Every state

Landslide risk by state: FEMA's model

The record above counts what happened. FEMA's National Risk Index estimates what each state can expect to lose to landslides and avalanches in an average year, from history, exposure and vulnerability: Puerto Rico carries the largest expected annual loss ($291M), then California and Colorado.

  1. Puerto Rico $291M
  2. California $153M
  3. Colorado $107M
  4. Washington $83M
  5. Alaska $73M
  6. Utah $57M
  7. Montana $54M
  8. Idaho $41M
  9. Wyoming $40M
  10. Oregon $9.9M
  11. North Carolina $8.9M
  12. Tennessee $5.3M
  13. New Hampshire $5.3M
  14. Hawaii $4.1M
  15. West Virginia $3.6M

Source: FEMA National Risk Index (December 2025), county expected annual loss summed by state; a model, not a count. FEMA's National Risk Index map.

When is the slide season?

Landslides and avalanches by month, nationally. The busiest month is February.

The values, month by month

Jan 476 · Feb 516 · Mar 348 · Apr 271 · May 240 · Jun 121 · Jul 294 · Aug 319 · Sep 179 · Oct 173 · Nov 167 · Dec 312 (records).

Source: NOAA NCEI Storm Events Database, records by the month they began, since 1996.

The deadliest landslide and avalanche records on record

The 10 storms with the most deaths since 1996, by state
DateRecordCharacterKilledInjuredDamage
2014-03-22 Debris FlowOso, Snohomish County, WA On a warm and dry 22nd of March, 2014, a large landslide occurred four miles east of the town of Oso, Washington. The slide debris, traveling at over 60 miles per hour, crossed the entire river valley, covering an area of over a square mile with an approximate deposit thickness of 15 to 75 feet in some areas. The ... 43 12 $75M
2018-01-09 Debris FlowSummerland, Santa Barbara County, CA Intense rainfall generated a large and deadly mud and debris flow in the community of Montecito, around the burn scar of the Thomas fire. Automated rain gauges in the area indicated very intense rainfall, reaching as high as 0.54 inches in 5 minutes. The intense rainfall resulted in a mud and debris estimated to be 15 ... 21 168 $725M
2003-12-25 Debris FlowSan Bernardino County, CA · forecast zone San Bernardino County Mountains Steady light to moderate rain began falling over the burned areas of the San Bernardino Mountains on 0600 PST 12/24/03. Approximately 24 hours later, mud, rock, and debris flows were being reported along highways and roads leading into the mountain resort communities. By 0800 PST on Christmas Day, more than two inches ... 14 10 $8.0M
2024-09-27 Hurricane Helene · Debris FlowBlue Ridge, Buncombe County, NC A large debris flow developed along Old Fort Rd in the Fairview area, destroying multiple homes and killing 11 members of the same family. A second large debris flow later developed and killed two emergency workers responding to the first event. 13 0 $941K
2005-01-10 Debris FlowSanta Barbara County, CA · forecast zone Santa Barbara County South Coast A powerful Pacific storm brought heavy rain, snow, flash flooding, high winds and landslides to Central and Southern California. During the 5 day event, rainfall totals ranged from 3 to 10 inches over coastal areas with up to 32 inches in the mountains. With such copious rainfall, flash flooding was a serious problem ... 10 0 –
2026-02-15 AvalancheAlpine County and 3 more, CA · forecast zone Greater Lake Tahoe Area Nevada Co Sheriff responded to a report of avalanche just north of Frog Lake near Castle Peak during the afternoon on the 17th. The avalanche caught a buried 15 backcountry skiers, resulting in 9 fatalities. 9 0 –
2023-11-20 Debris FlowWrangell, AK One storm episode: 2 records in 2 places; the totals are the episode's. A hurricane-force 964 mb low lifted out of the North Pacific and into the Gulf of Alaska through the early morning hours of November 20, 2023. This low-pressure system continued on a north-northwest track, with the warm front moving over the southern and central Panhandle through the day and the front pushing north ... 6 1 $2.1M
1999-03-21 AvalancheCook Inlet, AK · forecast zone Cook Inlet A tragic avalanche, adjacent to Turnagain Pass on Saturday, took the lives of 6 people. After days of searching by many volunteers, 5 bodies were recovered. The avalanche was triggered by snowmachiners 'high-marking' on the mountain slope during a warm, sunny day...after heavy snows several days before. 6 0 $44K
2007-12-01 AvalancheKing County and 2 more, WA · forecast zone West Slopes Central Cascades And Passes One storm episode: 2 records, 2007-12-01 to 2007-12-02; the totals are the episode's. Two hikers were killed, and one injured, by an avalanche near Snoqualmie Pass. 3 snowboarders are presumed dead near Crystal Mountain. The snowfall that led to the avalanches was part of a deep Pacific storm system offshore the also created lowland snow in western Washington, strong winds particularly in the coastal ... 5 1 –
2013-04-20 AvalancheBoulder County and 4 more, CO · forecast zone S & Se Grand / W Central & Sw Boulder / Gilpin / Clear Creek / Summit / N & W Park Counties Above 9000 Feet A large avalanche killed five snowboarders over Loveland Pass. 5 0 –

Source: NOAA NCEI Storm Events Database: deaths direct and indirect, as filed, summed over each storm in each state (one episode, or a named storm filed by several offices); names from FEMA declaration titles.

The costliest landslide and avalanche records since 1993

The 8 most damaging storms since 1993, 2025 dollars
DateRecordCharacterKilledInjuredDamage
2018-01-09 Debris FlowSummerland, Santa Barbara County, CA 21 168 $725M
2021-07-29 Debris FlowShoshone, Garfield County, CO One storm episode: 2 records in 2 places; the totals are the episode's. 0 0 $137M
2014-03-22 Debris FlowOso, Snohomish County, WA 43 12 $75M
2007-10-03 Debris FlowSan Diego County, CA · forecast zone San Diego County Coastal Areas 0 0 $68M
2006-04-01 Debris FlowMarin County and 2 more, CA · forecast zone North Bay Interior Valleys 1 0 $50M
2025-07-08 Debris FlowAlto, Lincoln County, NM 3 2 $50M
2005-12-28 Debris FlowDel Norte County and 2 more, CA · forecast zone North Coast Interior One storm episode: 5 records in 4 places; the totals are the episode's. 0 0 $45M
2005-06-01 Debris FlowOrange County, CA · forecast zone Orange County Coastal Plain 0 5 $41M

Source: NOAA NCEI Storm Events Database: damage as estimated by the National Weather Service, in 2025 dollars.

What the record files under landslides and avalanches

NOAA event types in this group
Event typeRecordsYearsKilledDamage
Debris Flow2,5451996-2026153$1.7B
Avalanche8711996-2026463$7.3M

Source: NOAA NCEI Storm Events Database, event types as defined in NWS Instruction 10-1605.

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