Enter any address in Allegheny County, Pennsylvania to see its FEMA flood zone
Flash flooding from thunderstorms is the dominant flood character in Allegheny County. Over the past 30 years, the NOAA Storm Events Database recorded 496 flash flood events and 125 flood events. Recent examples include flash flooding on May 21, 2025, caused by heavy rain from thunderstorms, and on June 14, 2025, when slow-moving storms dropped 2-3 inches of rain per hour in some areas, leading to stranded vehicles and flooded homes.
The National Flood Insurance Program (NFIP) data shows that properties in Zone A have experienced the most claims, with an average payout of $19,303 and an average water depth of 4.5 feet. However, properties in Zone X and Zone X_Shaded have also seen significant claims with substantial payouts, averaging $20,882 and $13,345 respectively, and water depths of 2.7 and 2.4 feet. Homeowners in Zone A, as well as those in other flood zones, should pay close attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
379 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Allegheny County, Pennsylvania has recorded 621 flood-related events since 1996 according to NOAA's Storm Events Database, including 496 flash floods and 125 river or area floods. The county has received 18 federal disaster declarations, 5 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1972–2020)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms, Tornadoes, And Flooding | Severe Storm | Jun 26, 2013 |
| Hurricane Sandy | Hurricane | Oct 26, 2012 |
| Severe Winter Storms And Snowstorms | Snowstorm | Feb 5, 2010 |
| Hurricane Katrina | Hurricane | Aug 29, 2005 |
| Tropical Depression Ivan | Hurricane | Sep 17, 2004 |
| Severe Storms And Flooding Associated With Tropical Depression Frances | Severe Storm | Sep 8, 2004 |
| Severe Storms, Tornadoes,and Flooding | Severe Storm | May 31, 1998 |
| Severe Storms And Flooding | Flood | Jan 19, 1996 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | Jun 28, 2025 | 2.00K |
| Flash Flood | Jun 28, 2025 | 5.00K |
| Flash Flood | Jun 27, 2025 | 5.00K |
| Flash Flood | Jun 27, 2025 | 20.00K |
| Flash Flood | Jun 26, 2025 | 10.00K |
| Flash Flood | Jun 26, 2025 | 50.00K |
| Flash Flood | May 21, 2025 | 0.00K |
| Flash Flood | Jun 17, 2025 | 5.00K |
| Flash Flood | Jul 16, 2025 | 0.00K |
| Flash Flood | Jun 15, 2025 | 5.00K |
Flash Flood — Jun 28, 2025
A warm, moist airmass remained in place through the latter half of the month which allowed for daily shower and thunderstorm chances. Training storms was the primary factor to the resultant flash flooding as cells developed upshear of the initial updrafts in West Virginia, Ohio, and Pennsylvania. One of these storms did result in yet another round of flash flooding for portions of Wheeling WV.
Flash Flood — Jun 27, 2025
A warm, moist airmass remained in place through the latter half of the month which allowed for daily shower and thunderstorm chances. Training storms was the primary factor to the resultant flash flooding as cells developed upshear of the initial updrafts in West Virginia, Ohio, and Pennsylvania. One of these storms did result in yet another round of flash flooding for portions of Wheeling WV.
Flash Flood — Jun 26, 2025
A warm, moist airmass remained in place through the latter half of the month which allowed for daily shower and thunderstorm chances. Training storms was the primary factor to the resultant flash flooding as cells developed upshear of the initial updrafts in West Virginia, Ohio, and Pennsylvania. One of these storms did result in yet another round of flash flooding for portions of Wheeling WV.
Flash Flood — May 21, 2025
An occluding surface low slowly drifted across Ohio on May 21st. Bands of showers with embedded thunderstorms moved across southwest Pennsylvania. During the mid to late afternoon, one convective band, associated with ample 0-3km CAPE and surface vorticity, was able to generate four tornadoes across southwest PA. Three were relatively brief and weak, but one longer-track EF1 was noted in Washi...
Flash Flood — Jun 17, 2025
The stalled boundary began to lift north during the day on the 17th but remained the focus of diurnal convection. While the front did eventually shift off to the east on the 18th, additional storms were able to fire with the lingering moist airmass as an upper level disturbance approached.
Source: NOAA National Weather Service Storm Events Database.
Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).
FEMA assigns flood zone designations to areas in Allegheny County, Pennsylvania:
AE High Risk — 1% annual chance of flooding. Insurance required.
VE Very High Risk — Coastal flooding with wave action.
X (Shaded) Moderate Risk — 500-year floodplain.
X Low Risk — Outside major floodplains.
Properties in Allegheny County, Pennsylvania that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.
Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.
Visit FloodSmart.gov to find an agent and get a quote.