1,700 flood insurance claims·$47.6M paid·10 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Philadelphia County, Pennsylvania. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
Flash flooding from heavy rainfall and summer thunderstorms dominates Philadelphia County, supported by 143 flash flood events and 7 total flood-related deaths over the last 30 years. NOAA records show frequent severe weather driven by slow-moving cold fronts and pre-frontal troughs, such as consecutive heavy rain events in July 2025 and thunderstorms that caused flash flooding in August 2025.
Federal insurance data reveals that flood risks extend beyond high-risk zones. Zone A accounts for the highest volume of claims at 959, with an average payout of $44,854 and an average recorded water depth of 6 inches. However, properties in moderate-to-low risk areas also experience significant impacts. Zone X records 398 claims with an average payout of $32,666 and an average water depth of 9 inches, while Shaded Zone X and Unshaded Zone X account for 179 and 82 claims respectively.
Homeowners and real estate agents in Zone A should pay the closest attention due to the high frequency and severity of claims, while property owners in Zone X must also remain vigilant given the substantial average water depths recorded during past flood events.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
21% of Philadelphia County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
1,224 NFIP claims with a recorded rated flood zone, 1978 to date. The zone is the one FEMA used to rate that policy, which may not match today’s map. Source: OpenFEMA NFIP claims.
In flood insurance claims here that reported a flood depth, the average was 6 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 2020, with 251 claims and $8.8M paid.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
40 NOAA storm reports from Philadelphia County describe what happened, in the words of the forecasters who covered it. Read the Pennsylvania flood stories →
25 federal disaster declarations since 1965, 10 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Remnants Of Hurricane Ida | Aug 31, 2021 |
| Severe Winter Storm And Snowstorm | Jan 22, 2016 |
| Severe Winter Storm | Feb 4, 2014 |
| Hurricane Sandy | Oct 26, 2012 |
| Remnants Of Tropical Storm Lee | Sep 3, 2011 |
| Tropical Storm Lee | Sep 3, 2011 |
| Hurricane Irene | Aug 26, 2011 |
| Severe Winter Storms And Snowstorms | Feb 5, 2010 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
301 since 1996: 143 flash floods, 97 river or area floods and 58 coastal floods or surges.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 31, 2025 | — |
| Flash Flood | Aug 17, 2025 | — |
| Flash Flood | May 16, 2025 | — |
| Flash Flood | Aug 13, 2025 | — |
| Flash Flood | Jul 9, 2025 | — |
| Flash Flood | Jul 8, 2025 | — |
| Flash Flood | Jul 1, 2025 | — |
| Coastal Flood | Jan 13, 2024 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jul 31, 2025. A stationary front sparked off showers and thunderstorms across the forecast area. Flash flooding resulted.
Flash Flood · Aug 17, 2025. A cold front was responsible for afternoon and evening thunderstorms. A few of these thunderstorms caused flash flooding.
Flash Flood · May 16, 2025. Scattered thunderstorms developed along a slow moving warm front.
Flash Flood · Aug 13, 2025. A pre-frontal trough, or elongated area of low pressure, was responsible for thunderstorms and subsequent flash flooding.
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Philadelphia County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.