Pennsylvania floods
Every recorded flood since 1996 · 67 counties with a record
NOAA's Storm Events Database records 7,057 floods and flash floods in Pennsylvania from 1996 through June 30, 2026, about 237 a year since 2000. The deadliest was Tropical Storm Lee (September 7, 2011): 12 deaths, 1 injury and $386 million in damage in 2025 dollars across 30 records. Pennsylvania ranks 7th of 52 states and territories by count and 13th of 51 per square mile.
Floods in Pennsylvania, 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
- 7,0571996 to June 30, 2026
- A year since 2000
- 237average
- Deaths
- 110166 injuries
- Damage, 2025 dollars
- $4.2Bas filed
- Busiest year
- 2018513 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 Pennsylvania?
Pennsylvania averages about 237 floods and flash floods a year since 2000, 7th of 52 states and territories by count. The busiest year on record was 2018 (513). Per 10,000 square miles of land, Pennsylvania records 1577 floods and flash floods since 1996, 13th of 51 states and territories by that measure.
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.
Which counties in Pennsylvania have the most floods and flash floods?
Per square mile, Philadelphia County leads Pennsylvania: 196 days with a flood since 1996, 1459.1 per 1,000 square miles of land. By raw count, Allegheny County has the most flood records (626 since 1996); large counties collect more records simply by covering more ground, so the ranking counts days with a record per unit of area (a storm filed for several forecast zones adds several records but one day).
Source: NOAA NCEI Storm Events Database, days with a record in the county since 1996 per 1,000 square miles of land (Census Bureau 2024 Gazetteer); in brackets, the count of records.
When is flood season in Pennsylvania?
Pennsylvania's floods and flash floods by month. The busiest month is July (1,395 records).
The values, month by month
Jan 446 · Feb 184 · Mar 338 · Apr 388 · May 514 · Jun 1,220 · Jul 1,395 · Aug 1,023 · Sep 845 · Oct 198 · Nov 237 · Dec 269 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began, since 1996.
What were the deadliest floods and flash floods in Pennsylvania?
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2011-09-07 | Tropical Storm Lee · FloodDeodate, Dauphin County One named storm filed by several offices: 30 records in 3 episodes, 2011-09-07 to 2011-09-09; the totals are the storm's. Heavy rainfall from the remnants of Tropical Storm Lee produced widespread flooding, flash flooding and river flooding mainly near and to the east of the Susquehanna Valley from September 4-10. Several locations in the Susquehanna Basin came close to records set by Hurricane Agnes (June 1972) and a few points ... | 12 | 1 | $386M | |
| 2023-07-15 | Flash FloodBuckmanville, Bucks County Catastrophic flash flooding occurred in Upper Makefield Township, resulting in the loss of seven lives. A reliable rain gauge located within the township indicated that 4.64 inches of rain fell during the event which lasted less than 2 hours. Widespread roadway flooding occurred with many roads becoming impassable. ... | 7 | 0 | – | |
| 1999-09-16 | Hurricane Floyd · Flash FloodCountywide, Montgomery County One named storm filed by several offices: 7 records in 2 episodes; the totals are the storm's. Hurricane Floyd battered Eastern Pennsylvania (especially Southeast sections around Philadelphia) on September 16th and brought with it torrential and in some places record breaking rains and damaging winds. The hurricane caused widespread flash flooding as storm totals averaged around six inches in the Poconos and ... | 6 | 38 | $104M | |
| 1996-01-19 | Flash FloodCountywide, Lycoming County Six people died in Lycoming County along Lycoming Creek on Friday the 19th. A husband and wife age 77 and 75 were swept away when they tried to drive away from their home in rural Trout Run early in the afternoon. A 68 year old man was last seen in the late morning before he tried to drive away from his hunting cabin ... | 6 | 0 | – | |
| 2004-09-17 | Tropical Depression Ivan · FloodBlair County · forecast zone Blair One named storm filed by several offices: 44 records in 38 episodes, 2004-09-17 to 2004-09-28; the totals are the storm's. | 5 | 93 | $575M | |
| 2011-08-19 | Flash FloodSharpsburg, Allegheny County A NWS storm survey found that 2.5 inches of rain fell in one hour in a very urbanized 4.8 sq mi watershed just east of downtown Pittsburgh. Severe flash flooding developed on Washington Blvd resulting in four fatalities and up to 15 water rescues. A mother and two daughters were drowned inside a van when it became ... | 4 | 1 | $656K | |
| 1996-09-08 | Tropical Depression Fran · Flash FloodSouthern, Montgomery County One named storm filed by several offices: 3 records in 3 episodes; the totals are the storm's. Thunderstorms, which "trained" or moved over the same locations of Southern Montgomery County, caused widespread flash flooding, caused the death of a couple in Abington and about $20 million dollars in property damage. Up to 10 inches of rain within a three hour period. The 10 inches of rain was measured at the water ... | 4 | 0 | $38M | |
| 2021-09-01 | Hurricane Ida · Flash FloodKing Of Prussia, Montgomery County One storm episode: 13 records in 7 places; the totals are the episode's. Post Tropical Cyclone Ida brought heavy rain to eastern Pennsylvania on September 1. Rainfall totals were as high as 5 to 10 inches. The heavy rain caused significant flash flooding, mainly in the southeastern part of the state. It resulted in widespread property damage. There were several fatalities. | 4 | 0 | $386M | |
| 1996-01-19 | Flash FloodCountywide, Juniata County Four deaths occurred in Juniata County as a direct result of the flooding on the evening of Friday the 19th. Two females and two males in three separate cars were unable to cross Tuscarora Creek between Academia and Pleasant View due to a flooded bridge. They attempted to cross the stream on foot and were swept away. | 4 | 0 | – | |
| 1996-01-19 | FloodMontgomery County · forecast zone Montgomery One storm episode: 8 records in 8 places; the totals are the episode's. The combination of snowmelt from the previous week's two storms, unseasonably warm temperatures and an additional one to two inches of rain caused the flash flooding of almost every small stream and significant roadway flooding the afternoon and early evening hours on the 19th. Major flooding of the larger streams and ... | 3 | 3 | $72M |
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 Pennsylvania
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2004-09-17 | Tropical Depression Ivan · FloodBlair County · forecast zone Blair One named storm filed by several offices: 44 records in 38 episodes, 2004-09-17 to 2004-09-28; the totals are the storm's. | 5 | 93 | $575M | |
| 2011-09-07 | Tropical Storm Lee · FloodDeodate, Dauphin County One named storm filed by several offices: 30 records in 3 episodes, 2011-09-07 to 2011-09-09; the totals are the storm's. | 12 | 1 | $386M | |
| 2021-09-01 | Hurricane Ida · Flash FloodKing Of Prussia, Montgomery County One storm episode: 13 records in 7 places; the totals are the episode's. | 4 | 0 | $386M | |
| 1996-07-19 | Flash FloodPunxsutawney, Jefferson County | 0 | 0 | $188M | |
| 2006-06-27 | Flash FloodCountywide, Luzerne County | 3 | 0 | $146M | |
| 2006-06-27 | Flash FloodCountywide, Susquehanna County | 1 | 0 | $146M | |
| 1996-07-19 | Flash FloodShippenville, Clarion County | 1 | 1 | $141M | |
| 1999-09-16 | Hurricane Floyd · Flash FloodCountywide, Montgomery County One named storm filed by several offices: 7 records in 2 episodes; the totals are the storm's. | 6 | 38 | $104M |
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 Pennsylvania?
Pennsylvania'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 | Pennsylvania | United States | Pennsylvania's share |
|---|---|---|---|
| 1996-99 | 859 | 20,986 | 4.1% |
| 2000s | 2,101 | 54,913 | 3.8% |
| 2010s | 2,584 | 68,322 | 3.8% |
| 2020-26 | 1,513 | 43,563 | 3.5% |
Source: NOAA NCEI Storm Events Database.
The most recent floods and flash floods in Pennsylvania
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-06-28 | Flash FloodWall, Allegheny County | 0 | 0 | $3K | |
| 2026-06-28 | Flash FloodWilkins Township, Allegheny County | 0 | 0 | $3K | |
| 2026-06-28 | Flash FloodChurchill, Allegheny County | 0 | 0 | $5K | |
| 2026-06-28 | Flash FloodBridesburg, Philadelphia County | 0 | 0 | – | |
| 2026-06-28 | Flash FloodGermantown, Philadelphia County | 0 | 0 | $5K | |
| 2026-06-22 | Flash FloodElliottsville, Fayette County | 0 | 0 | $5K | |
| 2026-06-22 | Flash FloodWest Philadelphia, Philadelphia County | 0 | 0 | $30K | |
| 2026-06-22 | Flash FloodGermantown, Philadelphia County | 0 | 0 | $50K | |
| 2026-06-22 | Flash FloodHill Crest, Montgomery County | 0 | 0 | $5K | |
| 2026-06-15 | Flash FloodMedia, Delaware County | 0 | 0 | $5K | |
| 2026-06-14 | Flash FloodOverbrook, Philadelphia County | 0 | 0 | – | |
| 2026-06-14 | Flash FloodCrescentville, Philadelphia County | 0 | 0 | – |
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 Pennsylvania
FEMA has declared 38 disasters in Pennsylvania 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); 37 were major disasters, the latest on November 27, 2018.
| Declared | Number | Title | Areas named |
|---|---|---|---|
| 2018-11-27 | DR-4408 | Severe Storms and Flooding | 11 |
| 2016-12-02 | DR-4292 | Severe Storms and Flooding | 4 |
| 2013-10-01 | DR-4149 | Severe Storms, Tornadoes, and Flooding | 11 |
| 2011-09-12 | DR-4030 | Tropical Storm Lee | 34 |
| 2011-09-08 | EM-3340 | Remnants of Tropical Storm Lee | 42 |
| 2011-07-13 | DR-4003 | Severe Storms and Flooding | 5 |
| 2007-02-23 | DR-1684 | Severe Storms and Flooding | 8 |
| 2006-06-30 | DR-1649 | Severe Storms, Flooding, and Mudslides | 28 |
| 2005-04-14 | DR-1587 | Severe Storms and Flooding | 11 |
| 2004-09-19 | DR-1555 | Severe Storms and Flooding Associated With Tropical Depression Frances | 67 |
| 2004-08-06 | DR-1538 | Severe Storms and Flooding | 7 |
| 2003-09-26 | DR-1497 | Tropical Storms Henri and Isabel and Related Severe Storms and Flooding | 1 |
Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), through October 2, 2026. OpenFEMA dataset page.
Next
- Philadelphia County: the county's whole recordThe Pennsylvania county with the most floods and flash floods per square mile
- Floods across the United StatesEvery state ranked, by year and month
- Every natural hazard in PennsylvaniaTornadoes, floods, storms, heat and the federal declarations
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