Allegheny County, Pennsylvania: hazard history
What federal records show has already happened here: disaster declarations, storms, and flood insurance claims. This is a record of the past. It is not a forecast and not a hazard score.
At a glance
What this means
- The event NOAA recorded most often here is Thunderstorm Wind, with 1,067 records.
- The costliest single record is Thunderstorm Wind in 1998: $41.0M in property damage, in the dollars of that year.
- The deadliest record is Flash Flood in 2011, with 4 deaths.
- FEMA has declared 18 disasters that named this county, most often for flood.
- The worst year for flood insurance claims was 2004, with 1,221 claims.
What this can't tell you
- What happens next. Past events do not set the odds of the next one.
- Anything before 1996 from NOAA. That is when NOAA began recording every event type; earlier files hold only tornado, hail and wind, so they are left out on purpose.
- Today's cost. Damage and payments are in the dollars of the year they happened.
- A flood rate. NFIP counts claims but not how many homes were insured, and many flooded homes carry no flood insurance.
- Earthquakes, wildfire perimeters or radar-detected hail. Those records are not tied to counties.
Federal disaster declarations (FEMA)
FEMA declared 18 disasters that named Allegheny County between 1972 and 2020.
| Incident type | Disasters | Most recent |
|---|---|---|
| Flood | 5 | 1996 |
| Severe Storm | 4 | 2013 |
| Hurricane | 3 | 2012 |
| Snowstorm | 3 | 2010 |
| Biological | 2 | 2020 |
| Tornado | 1 | 1980 |
Most recent declarations
- DR-4506 2020 · Biological · Covid-19 Pandemic
- EM-3441 2020 · Biological · Covid-19
- DR-4149 2013 · Severe Storm · Severe Storms, Tornadoes, And Flooding
- EM-3356 2012 · Hurricane · Hurricane Sandy
- DR-1898 2010 · Snowstorm · Severe Winter Storms And Snowstorms
- EM-3235 2005 · Hurricane · Hurricane Katrina
- DR-1557 2004 · Hurricane · Tropical Depression Ivan
- DR-1555 2004 · Severe Storm · Severe Storms And Flooding Associated With Tropical Depression Frances
- DR-1219 1998 · Severe Storm · Severe Storms, Tornadoes,and Flooding
- DR-1093 1996 · Flood · Severe Storms And Flooding
Not counted above: 6 statewide declarations, which covered every county in Pennsylvania. A declaration is a decision to send federal help, not a measure of how bad an event was. Records run from 1953. Source: FEMA OpenFEMA Disaster Declarations Summaries.
Storms recorded by NOAA, by type
| Event type | Records | Deaths | Injuries | Property damage |
|---|---|---|---|---|
| Thunderstorm Wind | 1,067 | 2 | 74 | $68.9M |
| Flash Flood | 498 | 6 | 2 | $60.3M |
| Hail | 382 | 0 | 0 | $6K |
| Flood | 125 | 1 | 92 | $30.6M |
| Winter Weather | 69 | 0 | 0 | $0 |
| High Wind | 38 | 0 | 3 | $1.2M |
| Heavy Rain | 31 | 0 | 0 | $0 |
| Winter Storm | 22 | 2 | 1 | $0 |
| Strong Wind | 18 | 0 | 1 | $128K |
| Tornado | 17 | 0 | 50 | $15.2M |
| Heavy Snow | 15 | 0 | 0 | $0 |
| Lightning | 10 | 0 | 1 | $122K |
| Extreme Cold/Wind Chill | 8 | 0 | 0 | $0 |
| Ice Storm | 8 | 0 | 40 | $7K |
| Cold/Wind Chill | 7 | 0 | 0 | $0 |
| Lake-Effect Snow | 6 | 0 | 0 | $0 |
| Debris Flow | 3 | 0 | 0 | $15K |
| Drought | 2 | 0 | 0 | $0 |
| Excessive Heat | 1 | 1 | 0 | $0 |
Records start in 1996. Damage is NOAA's estimate at the time, in nominal dollars, and is often rounded; it is not insurance claims data. A storm that crossed two NOAA zones in this county is recorded, and counted, once per zone. A storm filed against a forecast zone is counted in every county that zone covers, with the whole storm's damage; do not add these figures across counties.
Year by year
NOAA storm event records in Allegheny County each year. The busiest year was 2025, with 192 records.
Show the numbers for every year
| Year | Records | Deaths | Property damage |
|---|---|---|---|
| 1996 | 57 | 1 | $5.3M |
| 1997 | 36 | 1 | $10.1M |
| 1998 | 78 | 0 | $54.5M |
| 1999 | 29 | 2 | $1.3M |
| 2000 | 33 | 0 | $11.2M |
| 2001 | 21 | 0 | $2.2M |
| 2002 | 39 | 1 | $10.3M |
| 2003 | 56 | 0 | $161K |
| 2004 | 37 | 1 | $26.2M |
| 2005 | 34 | 0 | $964K |
| 2006 | 16 | 0 | $136K |
| 2007 | 60 | 0 | $15.9M |
| 2008 | 27 | 0 | $1.3M |
| 2009 | 23 | 0 | $409K |
| 2010 | 41 | 0 | $1.3M |
| 2011 | 51 | 4 | $1.1M |
| 2012 | 122 | 0 | $1.9M |
| 2013 | 171 | 0 | $2.3M |
| 2014 | 70 | 0 | $414K |
| 2015 | 109 | 0 | $445K |
| 2016 | 57 | 0 | $534K |
| 2017 | 87 | 0 | $244K |
| 2018 | 106 | 0 | $12.1M |
| 2019 | 123 | 0 | $499K |
| 2020 | 103 | 0 | $743K |
| 2021 | 169 | 0 | $1.4M |
| 2022 | 80 | 1 | $265K |
| 2023 | 92 | 0 | $382K |
| 2024 | 182 | 0 | $12.3M |
| 2025 | 192 | 1 | $714K |
| 2026 | 26 | 0 | $26K |
Years with no record are left out of the table, not shown as zero.
Notable events
Costliest records
- Thunderstorm Wind · Jun 30, 1998$41.0MNOAA name: Allegheny County · 10 injuries · NOAA record 5669244
- Flood · Sep 17, 2004$26.0MNOAA name: NWS forecast zone · 1 death · 92 injuries · NOAA record 5422635
- Flash Flood · Aug 9, 2007$15.0MNOAA name: Allegheny County · NOAA record 53724
- Tornado · Jun 2, 1998$13.0MNOAA name: Allegheny County · 50 injuries · NOAA record 5668878
- Flash Flood · Jul 1, 1997$10.0MNOAA name: Allegheny County · 1 death · NOAA record 5623088
Deadliest records
- Flash Flood · Aug 19, 20114 deathsNOAA name: Allegheny County · $500K damage · 1 injury · NOAA record 334799
- Winter Storm · Jan 2, 19992 deathsNOAA name: NWS forecast zone · 1 injury · NOAA record 5685768
- Flash Flood · Jun 19, 19961 deathNOAA name: Allegheny County · NOAA record 5563375
- Flash Flood · Jul 1, 19971 deathNOAA name: Allegheny County · $10.0M damage · NOAA record 5623088
- Thunderstorm Wind · May 31, 20021 deathNOAA name: Allegheny County · $10.0M damage · 54 injuries · NOAA record 5299207
Each line is one NOAA record, linked to its page at NOAA. One large storm can appear more than once if NOAA recorded it in several zones of this county. Dollars are nominal.
Flood insurance claims (NFIP)
The National Flood Insurance Program paid $80.5M on 4,813 claims in Allegheny County from 1978 to 2024.
| Year | Claims | Paid |
|---|---|---|
| 2004 | 1,221 | $35.5M |
| 1996 | 495 | $6.5M |
| 2018 | 330 | $8.7M |
| 2013 | 180 | $2.9M |
| 2007 | 176 | $1.7M |
A count of claims, not a rate: NFIP publishes no count of insured homes beside it, and most flood damage is uninsured. Nominal dollars. Records run from 1978 to 2024; claims filed without a county code are not on any county page. Source: FEMA OpenFEMA FIMA NFIP Redacted Claims.
Hazard vulnerability analysis: the probability column for a facility in Allegheny County
A hazard vulnerability analysis rates each hazard for probability, impact, preparedness and response. Probability is the one column the county’s federal record can fill — NCEI storm events from 1996 to 2026 and FEMA declarations naming the county — and this is what it says for a facility here, on the 0–3 scale of the all-hazards structure surveyors expect. The other six columns are the facility’s own judgment about its building, and Calchis leaves them blank.
| Hazard | Prob. | Basis, from the county record |
|---|---|---|
| Hurricane / Tropical Storm | 3 | No events of this kind on the county's NCEI record over 31 years. 3 federal disaster declarations naming the county. |
| Severe Thunderstorm | 3 | 1,459 NCEI events over 31 years (47.06/yr). 4 federal disaster declarations naming the county. |
| Flood, External | 3 | 654 NCEI events over 31 years (21.10/yr). 5 federal disaster declarations naming the county. |
| Snow Fall / Blizzard / Ice Storm | 3 | 120 NCEI events over 31 years (3.87/yr). 3 federal disaster declarations naming the county. |
| High Wind (non-convective) | 3 | 56 NCEI events over 31 years (1.81/yr). No federal disaster declaration of this kind has named the county. |
| Tornado | 2 | 17 NCEI events over 31 years (0.55/yr). 1 federal disaster declaration naming the county. |
| Temperature Extremes | 2 | 16 NCEI events over 31 years (0.52/yr). No federal disaster declaration of this kind has named the county. |
| Epidemic | 2 | 2 federal disaster declarations naming the county. |
| Drought | 1 | 2 NCEI events over 31 years (0.06/yr). No federal disaster declaration of this kind has named the county. |
| Wild Fire | 1 | No events of this kind on the county's NCEI record over 31 years. No federal disaster declaration of this kind has named the county. |
| Earthquake | 1 | No federal disaster declaration of this kind has named the county. |
| Landslide | 1 | 3 NCEI events over 31 years (0.10/yr). No federal disaster declaration of this kind has named the county. |
| Tidal Wave / Tsunami | 1 | No events of this kind on the county's NCEI record over 31 years. No federal disaster declaration of this kind has named the county. |
| Volcano | 1 | No events of this kind on the county's NCEI record over 31 years. No federal disaster declaration of this kind has named the county. |
| Dam Inundation | 1 | No federal disaster declaration of this kind has named the county. |
A dash means the record does not speak to that hazard; it is not a zero. Whether a finished document satisfies the CMS Emergency Preparedness Rule is the facility’s finding and its surveyor’s. Complete the HVA for a facility in Allegheny County — the technological, human and hazardous-materials rows, the six facility columns, the approval and the printed document — or read the sample analysis on that page first.
How this page was made
- Every figure is counted from public federal records held by Calchis: NOAA NCEI Storm Events, FEMA OpenFEMA Disaster Declarations, and FEMA NFIP claims. Nothing is modeled or estimated.
- NOAA files some events against a county and others against an NWS forecast zone, and publishes a code for both. Records are counted as Allegheny County by that code — county records by the county's own FIPS code, zone records through the National Weather Service's published list of which counties each zone covers. No name matching is involved. Of 2,327 records, 2,105 were filed against this county and 222 against a forecast zone covering it. A zone storm is counted in every county its zone covers, and its damage figure is the whole storm's, not this county's share — NOAA does not publish that split. So these figures describe this county; they must not be added up across counties. Left out: 4% of Pennsylvania's NOAA records, which are marine zones or zones NWS does not map to a county.
- Counts last rebuilt from the source records on Sep 15, 2026.
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Recorded history from federal public records. Not a hazard score, a risk score, or a forecast, and not a substitute for professional actuarial or emergency-management assessment. Decision-support intelligence — not a primary alerting or dispatch system. Verify against official sources.