Guam floods
Every recorded flood since 1996 · 1 county with a record
NOAA's Storm Events Database records 89 floods and flash floods in Guam from 1996 through June 30, 2026, about 3.9 a year since 2000. The deadliest was Tropical Storm Tingting (June 27, 2004) in Guam: 1 death and $9.4 million in damage in 2025 dollars.
Floods in Guam, 1996 to 2026
Flood records per year (NOAA Storm Events); 2026 to June 30, 2026.
- recorded, no damage figure
- under $1 million
- $1 million or more
- $10 million or more
- $100 million or more, or 10 deaths
- $1 billion or more, or 100 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- Records
- 891996 to June 30, 2026
- A year since 2000
- 3.9average
- Deaths
- 10 injuries
- Damage, 2025 dollars
- $13Mas filed
- Busiest year
- 199926 records
Source: NOAA NCEI Storm Events Database, records through June 30, 2026; deaths and damage as filed, damage in 2025 dollars. Search the record at NCEI.
Are floods and flash floods common in Guam?
Guam averages about 3.9 floods and flash floods a year since 2000. The busiest year on record was 1999 (26).
Source: NOAA NCEI Storm Events Database, records since 1996, per 10,000 square miles of land area (Census Bureau 2024 Gazetteer; places under 1,000 square miles not ranked). Damage colours: Storm Events damage, 2025 dollars.
When is flood season in Guam?
43% of its floods and flash floods since 1996 fell in August and September. The busiest month is August (19 records).
The values, month by month
Jan 6 · Feb 2 · Mar 2 · Apr 1 · May 2 · Jun 6 · Jul 15 · Aug 19 · Sep 19 · Oct 10 · Nov 3 · Dec 4 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began, since 1996.
What were the deadliest floods and flash floods in Guam?
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2004-06-27 | Tropical Storm Tingting · Flash FloodCountywide, Guam TYPHOON TINGTINGAfter starting about 500 miles southeast of Saipan the evening of June 25th, Tropical Depression 11W moved steadily northwest, becoming Tropical Storm Tingting the following afternoon at 1600 SST. Tingting brought tropical storm conditions to Guam, Rota, Tinian and Saipan on the 28th, passing 70 miles ... | 1 | 0 | $9.4M |
Source: NOAA NCEI Storm Events Database: deaths direct and indirect, as filed by the National Weather Service, summed over each storm (one episode, or one named storm filed by several offices). Storm names from the titles of FEMA declarations that name the storm's counties.
The costliest floods and flash floods in Guam
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2004-06-27 | Tropical Storm Tingting · Flash FloodCountywide, Guam | 1 | 0 | $9.4M | |
| 2015-07-11 | Coastal FloodGuam · forecast zone Guam | 0 | 0 | $1.2M | |
| 2013-09-20 | FloodPiti, Guam One storm episode: 2 records; the totals are the episode's. | 0 | 0 | $887K | |
| 1999-07-30 | Flash FloodMerizo, Guam | 0 | 0 | $709K | |
| 2001-10-14 | FloodGuam · forecast zone Guam | 0 | 0 | $667K |
Source: NOAA NCEI Storm Events Database: property and crop damage as estimated by the National Weather Service, in 2025 dollars.
Are floods and flash floods becoming more frequent in Guam?
Guam's count per decade against the whole country's, and its share. NOAA recorded every event type only from 1996, so earlier decades are not comparable; the share of the national total is the fairer comparison across decades.
| Decade | Guam | United States | Guam's share |
|---|---|---|---|
| 1996-99 | 38 | 20,986 | 0.18% |
| 2000s | 29 | 54,913 | 0.05% |
| 2010s | 5 | 68,322 | 0.01% |
| 2020-26 | 17 | 43,563 | 0.04% |
Source: NOAA NCEI Storm Events Database.
The most recent floods and flash floods in Guam
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2015-07-11 | Coastal FloodGuam · forecast zone Guam | 0 | 0 | $1.2M | |
| 2013-09-20 | FloodPiti, Guam | 0 | 0 | $633K | |
| 2013-09-19 | FloodYona, Guam | 0 | 0 | $253K | |
| 2004-06-27 | Flash FloodCountywide, Guam | 1 | 0 | $9.4M | |
| 2001-10-14 | FloodGuam · forecast zone Guam | 0 | 0 | $667K | |
| 1999-07-30 | Flash FloodMerizo, Guam | 0 | 0 | $709K |
Source: NOAA NCEI Storm Events Database, records through June 30, 2026; the newest months are revised by NCEI as reports arrive. Search the record at NCEI.
Federal disaster declarations for floods and flash floods in Guam
FEMA has declared 1 disaster in Guam for floods and flash floods, counting its incident type and declarations that name flood in the title (FEMA files most storm disasters under Severe Storm); one was a major disaster, the latest on July 29, 2004.
| Declared | Number | Title | Areas named |
|---|---|---|---|
| 2004-07-29 | DR-1533 | High Winds, Flooding, and Mudslides As A Result of Tropical Storm Tingting | 1 |
Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), through October 2, 2026. OpenFEMA dataset page.