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Delaware County, Pennsylvania severe weather history spans 671 recorded events between 1957 and 2026. The dominant hazard is thunderstorm wind, accounting for 49.3% of all recorded events. It ranks #445 nationally and #18 in Pennsylvania.
671
Recorded events
3
Direct deaths
38
Direct injuries
$77.8M
Property damage
The record
What the Delaware County, Pennsylvania severe weather history record shows
Across the archive, Delaware County, Pennsylvania severe weather history averages 9.7 recorded events a year. The busiest stretch on record is the 2020s, with 222 events logged in that decade alone. Roughly 45 events fall before 1990 and 626 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Delaware County, Pennsylvania record is thunderstorm wind, responsible for 1 direct deaths. The costliest is flash flood, with $55.9M in reported property damage. In total, 9 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Delaware County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 331 | 1 | $7.7M | 91 | 1957–2026 |
| Flash Flood | 144 | 1 | $55.9M | 0 | 1996–2025 |
| Hail | 62 | 0 | $0 | 1.75 | 1957–2025 |
| Flood | 49 | 0 | $8.1M | 0 | 1998–2023 |
| Lightning | 39 | 1 | $864K | 0 | 1997–2017 |
| Heavy Rain | 35 | 0 | $0 | 0 | 1997–2017 |
| Tornado | 5 | 0 | $5.3M | F2 | 1973–2019 |
| Funnel Cloud | 5 | 0 | $0 | 0 | 1998–2021 |
| Wildfire | 1 | 0 | $0 | 0 | 2001–2001 |
Decade by decade
Delaware County, Pennsylvania severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
6 mapped tornado paths intersect this county: 6 touched down inside it and 0 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 2019-10-31 | EF2 | 0 | 2 | 0.5 mi | Touched down here |
| 1973-06-29 | EF2 | 0 | 0 | 1.9 mi | Touched down here |
| 1994-04-16 | EF1 | 0 | 0 | 0.3 mi | Touched down here |
| 1993-09-27 | EF1 | 0 | 0 | 3.0 mi | Touched down here |
| 1992-07-15 | EF1 | 0 | 0 | 0.7 mi | Touched down here |
| 2010-08-22 | EF0 | 0 | 0 | 0.3 mi | Touched down here |
Significant events
Deadliest events on record in Delaware County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Sep 16, 1999 | Flash Flood | COUNTYWIDE | 1 | 14 | $15.0M |
| Oct 15, 2003 | Thunderstorm Wind | HAVERFORD | 1 | 1 | $0 |
| Jun 2, 2006 | Lightning | BOOTHWYN | 1 | 0 | $0 |
| May 16, 2004 | Thunderstorm Wind | YEADON | 0 | 8 | $0 |
| Mar 22, 2000 | Flash Flood | COUNTYWIDE | 0 | 3 | $0 |
| Nov 1, 2019 | Tornado | GLEN MILLS | 0 | 2 | $0 |
| Jun 24, 2010 | Thunderstorm Wind | FLORIDA PARK | 0 | 2 | $1.0M |
| Jul 23, 2008 | Lightning | BOOTH CORNER | 0 | 2 | $1K |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Chester City was also hard hit by the powerful macroburst associated with the line of severe thunderstorms. About twenty homes and buildings were condemned because of wind damage including fallen trees. Buildings along the Avenue Of The States as well as trees within city parks were particularly hard hit. A tractor-trailer along Interstate 95 was overturned by the severe thunderstorm. the driver was not injured. Wind damage in the city was estimated at 2.5 million dollars.
An extremely powerful macroburst associated with a severe thunderstorm cut a swath of wind damage across the eastern side of Aston Township to the east of Concord Road. Peak wind gusts were estimated to reach 85 mph. Shingles and siding was ripped from homes as well as numerous homes that were struck by fallen trees. About fifteen homes were condemned in the township. Wind damage from the macroburst continued southeast through Chester City.
Heavy rain caused flash flooding along Cobbs Creek and other small streams particularly in the eastern half of Delaware County. Many water rescues from trapped vehicles occurred. Hardest hit was Haverford Township. Doppler Radar storm total estimates reached between 3 and 4 inches in the northeast part of the county. ||In Haverford Township, an emergency disaster was declared. Homes bordering Cobbs Creek and its tributaries were damaged. On Eagle Road, cars were submerged and homes were surrounded by water. Roads and bridges on Hathaway Lane were damaged. Homes and vehicles on Wynnefield Drive were flooded. Six roads in the township were flooded. In Darby Borough, flood waters from the Darby Creek washed away a portion of McDade Boulevard. Ten residents were evacuated from Springfield Road. Roadway and basement flooding also occurred in Lansdowne Borough and Chester City. The precipitation event total at the Philadelphia International Airport was 1.59 inches.
Context
Risk, population and federal disasters
Relatively Moderate
FEMA NRI risk rating
579,222
Population (ACS)
$332K
Median home value
24
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Sep 10, 2021 | Hurricane | REMNANTS OF HURRICANE IDA | DR |
| Mar 30, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| Feb 6, 2014 | Severe Ice Storm | SEVERE WINTER STORM | EM |
| Oct 29, 2012 | Hurricane | HURRICANE SANDY | EM |
| Sep 12, 2011 | Flood | TROPICAL STORM LEE | DR |
Quick answers
Frequently asked
How many severe weather events have been recorded in Delaware County, Pennsylvania?
671 events are on record between 1957 and 2026, causing 3 direct deaths and $77.8M in property damage.
What is the most common severe weather hazard in Delaware County?
Thunderstorm Wind, with 331 recorded events — 49.3% of everything in the archive for this county.
How many tornadoes have crossed Delaware County?
6 mapped tornado paths intersect the county boundary; 6 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Delaware County?
24 federal disaster declarations from FEMA include Delaware County, each tied to a specific incident period.
How risky is Delaware County compared with the rest of the country?
FEMA's National Risk Index rates Delaware County as relatively moderate risk, placing it in the 93 percentile of its state for expected annual loss.
Where does the Delaware County, Pennsylvania severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Dauphin County 553
- Elk County 239
- Cumberland County 429
- Erie County 711
- Crawford County 784
- Fayette County 767
Cite this page
“Delaware County, Pennsylvania.” Severe Weather History. severeweatherhistory.com/county/pennsylvania/delaware-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.