Delaware County, Pennsylvania
County storm and disaster record · FIPS 42045 · population 576,366 · 184 sq mi
NOAA's Storm Events Database holds 1,367 records for Delaware County, Pennsylvania from 1950 through June 30, 2026, on 944 days; the most frequent are severe thunderstorm wind events (338 records). The deadliest single record is the July 4, 1999 heat, filed for the forecast zone Delaware, which covers the county: 7 deaths. FEMA has issued 24 declarations naming the county since 1965, 22 of them for natural hazards; the latest for a natural hazard was “Remnants of Hurricane Ida” on September 10, 2021.
The record, 1950 to 2026
Storm records filed for the county each year (2026 to June 30, 2026). Before 1996 NOAA recorded only tornadoes (from 1950), thunderstorm wind and hail (from 1955).
- recorded, no damage figure
- under $100,000
- $100,000 or more
- $1 million or more
- $10 million or more, or a death
- $100 million or more, or 10 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- 1955: wind and hail recorded from 1955
- 1996: all 48 event types from 1996
- Storm records
- 1,367on 944 days, 1950 to June 30, 2026
- Deaths recorded
- 25109 injuries
- Damage, 2025 dollars
- $130Mas filed (scale steps before 1993)
- Tornadoes
- 5strongest EF2
- FEMA declarations
- 24latest 2021
Source: NOAA NCEI Storm Events Database, records through June 30, 2026 (file revision 20260918); damage converted to 2025 dollars with the BLS CPI-U. Search the record at NCEI. BLS consumer price index.
What hazards hit Delaware County most?
The most frequent records are severe thunderstorm wind events: 338 since 1957. 50% of its severe thunderstorm wind events since 1957 fell in June and July. The rank column places the county among Pennsylvania's counties by days with a record per 1,000 square miles of land over each hazard's complete period.
| Hazard | Records | Days | First, last | Killed | Injured | Damage | Rank in state |
|---|---|---|---|---|---|---|---|
| Severe thunderstorm wind | 338 | 187 | 1957-2026 | 2 | 18 | $10M | 2 of 67 |
| Floods | 258 | 163 | 1996-2026 | 1 | 17 | $87M | 2 of 67 |
| Winter storms | 214 | 212 | 1996-2026 | 5 | 32 | $7.7M | 3 of 67 |
| High wind and dust storms | 140 | 138 | 1996-2026 | 1 | 7 | $12M | 2 of 67 |
| Heat | 103 | 103 | 1996-2026 | 12 | 28 | – | 2 of 67 |
| Hail | 63 | 37 | 1957-2026 | 0 | 0 | – | 4 of 67 |
| Heavy rain | 45 | 44 | 1996-2017 | 0 | 0 | – | 2 of 67 |
| Drought | 44 | 44 | 1997-2010 | 0 | 0 | – | 2 of 67 |
| Fog, smoke and funnel clouds | 40 | 39 | 1998-2026 | 0 | 0 | – | 2 of 67 |
| Lightning | 39 | 28 | 1997-2017 | 1 | 5 | $1.2M | 1 of 67 |
| Extreme cold | 30 | 30 | 1996-2022 | 3 | 0 | – | 2 of 67 |
| Rip currents and high surf | 25 | 25 | 2007-2016 | 0 | 0 | – | 2 of 67 |
| Hurricanes and tropical storms | 20 | 18 | 2003-2020 | 0 | 0 | $656K | 2 of 67 |
| Tornadoes | 5 | 5 | 1973-2019 | 0 | 2 | $11M | 23 of 67 |
| Wildfires | 3 | 3 | 2001-2012 | 0 | 0 | $13K | 5 of 67 |
Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.
How many tornadoes has Delaware County had?
NOAA records 5 tornadoes in Delaware County from 1973 to 2019, the strongest rated EF2, with 0 deaths and 2 injuries recorded in the county. That is 23rd of 67 Pennsylvania counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.
Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 6 tornadoes whose track touched Delaware County since 1950 (NOAA's county records number 5: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 0 people.
Map of the strongest tornado tracks in Pennsylvania.
Every tornado record filed for Delaware County (5)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2019-10-31 | Glen Mills, Delaware County | EF2 0.47 mi x 250 yd | 0 | 2 | – |
| 2010-08-22 | Trainer, Delaware County | EF0 0.33 mi x 80 yd | 0 | 0 | $34K |
| 1993-09-27 | Springfield, Delaware County | F1 3 mi x 200 yd | 0 | 0 | $10M |
| 1992-07-15 | Delaware County | F1 0.7 mi x 100 yd | 0 | 0 | $250K step |
| 1973-06-29 | Delaware County | F2 1.9 mi x 63 yd | 0 | 0 | $25K step |
A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.
Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.
When was the last damaging storm in Delaware County?
The most recent record with damage, injuries or deaths is the June 15, 2026 flash flood ($5,000 in damage in 2025 dollars).
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-06-22 | Thunderstorm WindChester, Delaware County | 50 kt wind | 0 | 0 | – |
| 2026-06-15 | Flash FloodMedia, Delaware County | 0 | 0 | $5K | |
| 2026-06-14 | Thunderstorm WindBroomall, Delaware County | 50 kt wind | 0 | 0 | – |
| 2026-06-14 | Thunderstorm WindRadnor, Delaware County | 50 kt wind | 0 | 0 | – |
| 2026-06-14 | Thunderstorm WindGlenolden, Delaware County | 50 kt wind | 0 | 0 | – |
| 2026-06-14 | Thunderstorm WindBroomall, Delaware County | 50 kt wind | 0 | 0 | – |
| 2026-06-14 | Thunderstorm WindMedia, Delaware County | 50 kt wind | 0 | 0 | – |
| 2026-06-14 | Flash FloodBriarcliff, Delaware County | 0 | 0 | $5K | |
| 2026-06-14 | Flash FloodDrexel Plaza, Delaware County | 0 | 0 | $5K | |
| 2026-06-14 | Flash FloodAston Mills, Delaware County | 0 | 0 | $5K | |
| 2026-06-11 | Excessive HeatDelaware County · forecast zone Delaware | 0 | 0 | – | |
| 2026-05-20 | Thunderstorm WindDarling, Delaware County | 55 kt wind | 0 | 0 | – |
Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.
The deadliest and costliest records
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 1999-07-04 | HeatDelaware County · forecast zone Delaware A very strong and oppressive high pressure system that extended from the surface to aloft gave Eastern Pennsylvania a brutal heat wave that included the entire Independence Day weekend. There were 74 heat related deaths and over 100 reported heat related injuries. High temperatures reached the 90s for the first time ... | 7 | 0 | – | |
| 2014-01-22 | Cold/Wind ChillDelaware County · forecast zone Delaware Strong northwest winds behind the departing strong low pressure system coupled with another arctic air mass dropped low temperatures on the morning of the 22nd around zero (well below zero in the Poconos) and produced wind chill factors as low as around 15 degrees below zero, except around 25 degrees below zero in the ... | 3 | 0 | – | |
| 2015-01-18 | Winter WeatherDelaware County · forecast zone Delaware Freezing rain at the onset of a protracted precipitation event resulted in hundreds of accidents, two that had fatalities, across Eastern Pennsylvania during the morning into the early afternoon of the 18th. There were also numerous pedestrian slip and fall accidents. A confluence of meteorological events made it easy ... | 2 | 20 | – | |
| 2010-07-16 | Excessive HeatDelaware County · forecast zone Delaware Another heat wave brought high temperatures into the upper 90s on the 16th and five days in a row of 90 plus temperatures to Southeastern Pennsylvania. While July 16th was the hottest and most humid day (afternoon heat indices of around 100F). It took a series of cold fronts to whittle away at the heat. The last front ... | 2 | 0 | – | |
| 2008-06-07 | Excessive HeatDelaware County · forecast zone Delaware The most oppressive heat wave of the meteorological summer affected Eastern Pennsylvania from June 7th through the 10th. There were about twenty heat related deaths, eighteen within Philadelphia. There were also a couple of drownings within rivers. The combination of high temperatures well into the 90s and dew point ... | 1 | 22 | – | |
| 1999-09-16 | Flash FloodCountywide, Delaware County 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 ... | 1 | 14 | $27M | |
| 2003-10-14 | Thunderstorm WindHaverford, Delaware County A line of severe thunderstorms caused wind damage in Delaware County and hit Haverford and Tinicum Townships the hardest. A 24-year-old male was killed when a falling tree landed on and crushed his Sports Utility Vehicle while he was driving on Marple Avenue in Haverford Township. He died from head injuries. His ... | 56 kt wind | 1 | 1 | – |
| 2020-06-03 | Thunderstorm WindCrum Creek Manor, Delaware County A tree fell on a power line that fell on a house near Wallingford, which then started a house fire, killing one individual. Time estimated from radar. | 52 kt wind | 1 | 0 | – |
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 1999-09-16 | Flash FloodCountywide, Delaware County | 1 | 14 | $27M | |
| 2021-09-01 | Flash FloodEdgemont, Delaware County | 0 | 0 | $16M | |
| 2004-08-01 | Flash FloodEast Portion, Delaware County | 0 | 0 | $16M | |
| 1993-09-27 | TornadoSpringfield, Delaware County | F1 3 mi x 200 yd | 0 | 0 | $10M |
| 2003-09-18 | High WindDelaware County · forecast zone Delaware | 50 kt wind | 0 | 0 | $8.4M |
| 2010-10-01 | FloodChadds Ford, Delaware County | 0 | 0 | $6.8M | |
| 2010-02-09 | Winter StormDelaware County · forecast zone Delaware | 0 | 0 | $3.4M | |
| 2015-06-23 | Thunderstorm WindChester, Delaware County | 65 kt wind | 0 | 0 | $3.1M |
Before 1993 NOAA filed damage by category, not amount, so the list above starts in 1993. The highest category filed here before then (entered as $250K, in the dollars of the day) holds: July 15, 1992 (tornado, Delaware County).
Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.
Is it getting more frequent?
Records per decade for Delaware County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).
| Hazard | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020-26 |
|---|---|---|---|---|---|---|---|---|
| Severe thunderstorm wind | 4 | 5 | 8 | 20 | 33 | 48 | 89 | 131 |
| Floods | – | – | – | – | 21 | 59 | 87 | 91 |
| Winter storms | – | – | – | – | 17 | 76 | 89 | 32 |
| High wind and dust storms | – | – | – | – | 19 | 68 | 47 | 6 |
| Heat | – | – | – | – | 27 | 38 | 24 | 14 |
| Hail | 1 | 2 | 1 | 3 | 6 | 12 | 17 | 21 |
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
50% of its severe thunderstorm wind events since 1957 fell in June and July. The two busiest months are in violet.
The values, month by month
Jan 146 · Feb 148 · Mar 96 · Apr 78 · May 79 · Jun 181 · Jul 182 · Aug 152 · Sep 76 · Oct 58 · Nov 63 · Dec 108 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Delaware County
FEMA's register lists 24 declarations that include Delaware County: 16 major disasters, 8 emergencies and 0 fire management assistance declarations. Most were for hurricane (7) and flood (6).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2021-09-10 | DR-4618 | Hurricane | Remnants of Hurricane Ida |
| 2020-03-30 | DR-4506 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3441 | Biological | Covid-19 |
| 2014-02-06 | EM-3367 | Severe Ice Storm | Severe Winter Storm |
| 2012-10-29 | EM-3356 | Hurricane | Hurricane Sandy |
| 2011-09-12 | DR-4030 | Flood | Tropical Storm Lee |
| 2011-09-08 | EM-3340 | Flood | Remnants of Tropical Storm Lee |
| 2011-09-03 | DR-4025 | Hurricane | Hurricane Irene |
| 2011-08-29 | EM-3339 | Hurricane | Hurricane Irene |
| 2010-04-16 | DR-1898 | Snowstorm | Severe Winter Storms and Snowstorms |
| 2005-09-10 | EM-3235 | Hurricane | Hurricane Katrina |
| 2004-09-19 | DR-1555 | Severe Storm | Severe Storms and Flooding Associated With Tropical Depression Frances |
| 2004-09-19 | DR-1557 | Hurricane | Tropical Depression Ivan |
| 2004-08-06 | DR-1538 | Severe Storm | Severe Storms and Flooding |
| 2003-03-14 | EM-3180 | Severe Storm | Snow |
| 1999-09-18 | DR-1294 | Hurricane | Hurricane Floyd Major Disaster Declarations |
| 1996-01-21 | DR-1093 | Flood | Severe Storms and Flooding |
| 1996-01-13 | DR-1085 | Snowstorm | Blizzard of 96 |
| 1994-03-10 | DR-1015 | Severe Storm | Severe Winter Storms |
| 1993-03-16 | EM-3105 | Snowstorm | Severe Snowfall & Winter Storm |
| 1973-07-17 | DR-400 | Flood | Severe Storms & Flooding |
| 1972-06-23 | DR-340 | Flood | Tropical Storm Agnes |
| 1971-09-18 | DR-312 | Flood | Floods |
| 1965-08-18 | DR-206 | Drought | Water Shortage |
Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.
How many floods has Delaware County had?
NOAA's Storm Events Database holds 258 flood or flash flood records for Delaware County from 1996 to 2026, on 163 days, with 1 death. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Delaware County ranks 139th of 2,942 U.S. counties.
| Storm | Began | Records | Deaths in the county |
|---|---|---|---|
| Hurricane Floyd | 1999-09-16 | 1 | 1 |
| Hurricane Ida | 2021-09-01 | 2 | 0 |
| Hurricane Irene | 2011-08-27 | 2 | 0 |
The National Flood Insurance Program has paid $57.2 million on 3,034 claims filed in Delaware County; the most in one year was 509 in 1999. Claims count insured losses only: uninsured flood damage is not in this file.
The values, year by year
1978: 61 · 1979: 125 · 1980: 26 · 1981: 36 · 1982: 6 · 1983: 11 · 1984: 52 · 1985: 18 · 1986: 1 · 1987: 4 · 1988: 8 · 1989: 127 · 1990: 14 · 1991: 86 · 1992: 14 · 1993: 16 · 1994: 77 · 1995: 4 · 1996: 55 · 1997: 6 · 1999: 509 · 2000: 18 · 2001: 24 · 2002: 5 · 2003: 82 · 2004: 334 · 2005: 18 · 2006: 11 · 2007: 27 · 2008: 7 · 2009: 29 · 2010: 326 · 2011: 314 · 2012: 35 · 2013: 24 · 2014: 53 · 2015: 9 · 2016: 9 · 2017: 5 · 2018: 77 · 2019: 37 · 2020: 268 · 2021: 35 · 2023: 8 · 2024: 14 · 2025: 7 · 2026: 2; the other years: 0.
Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.
FEMA's modeled risk for Delaware County
FEMA's National Risk Index rates Delaware County Relatively Moderate overall, with an expected annual loss of $135 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.
| Hazard | Risk rating | Expected annual loss | Modeled frequency |
|---|---|---|---|
| Winter Weather | Very High | $2.1M | 10 a year (modeled) |
| Strong Wind | Relatively High | $5.2M | 6.9 a year (modeled) |
| Heat Wave | Relatively High | $13M | 11 modeled event-days a year |
| Lightning | Relatively High | $2.1M | 36 a year (modeled) |
| Riverine Flooding | Relatively High | $74M | 4.6 a year (modeled) |
| Tornado | Relatively High | $9.4M | once in about 10 years (modeled) |
| Cold Wave | Relatively High | $8.5M | about once a year (modeled) |
| Ice Storm | Relatively High | $750K | 1.4 a year (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Delaware County
Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.
Next
- Tornadoes in PennsylvaniaEvery Pennsylvania tornado since 1950 and the counties with the most per square mile
- Severe thunderstorm wind in PennsylvaniaThe state's severe thunderstorm wind events, by county, year and month
- The Pennsylvania recordEvery hazard in the state, its deadliest events and its federal declarations
- FEMA's risk rating for each hazard in Delaware CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Delaware County's FEMA declarations (CSV)24 rows: every declaration that named the county, for your own analysis