Enter any address in Chester County, Pennsylvania to see its FEMA flood zone
Flash flooding from slow-moving weather systems is the dominant flood character in Chester County. Over the past 30 years, NOAA Storm Events data shows 223 flash flood events, alongside 70 other flood events and 2 tropical storm events. For example, on July 25th, a slow-moving cold front produced heavy rain and flash flooding across portions of the region, an event that repeated the following day.
National Flood Insurance Program (NFIP) claims data indicates that properties in Zone A have experienced the highest number of claims, with 1085 claims filed. However, properties in Zone X, which includes both shaded and unshaded areas, have seen higher average payouts and water depths in some instances. Homeowners in Zone A, as well as those in Zone X, should pay close attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
42 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Chester County, Pennsylvania has recorded 295 flood-related events since 1996 according to NOAA's Storm Events Database, including 223 flash floods and 70 river or area floods. The county has received 26 federal disaster declarations, 6 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1965–2021)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Remnants Of Hurricane Ida | Hurricane | Aug 31, 2021 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Winter Storm And Snowstorm | Snowstorm | Jan 22, 2016 |
| Severe Winter Storm | Severe Ice Storm | Feb 4, 2014 |
| Hurricane Sandy | Hurricane | Oct 26, 2012 |
| Remnants Of Tropical Storm Lee | Flood | Sep 3, 2011 |
| Tropical Storm Lee | Flood | Sep 3, 2011 |
| Hurricane Irene | Hurricane | Aug 26, 2011 |
| Severe Winter Storms And Snowstorms | Snowstorm | Feb 5, 2010 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | Jun 27, 2025 | 0.00K |
| Flash Flood | Jun 27, 2025 | 10.00K |
| Flash Flood | May 16, 2025 | 0.00K |
| Flash Flood | May 16, 2025 | 15.00K |
| Flash Flood | May 16, 2025 | 10.00K |
| Flash Flood | May 16, 2025 | 20.00K |
| Flash Flood | Jul 9, 2025 | 0.00K |
| Flash Flood | Jul 9, 2025 | 5.00K |
| Flash Flood | Jul 9, 2025 | 20.00K |
| Flash Flood | Jul 8, 2025 | 0.00K |
Flash Flood — Jun 27, 2025
Showers and storms developed behind a backdoor cold front resulting in heavy rain.
Flash Flood — May 16, 2025
Scattered thunderstorms developed along a slow moving warm front.
Flash Flood — Jul 9, 2025
A slow-moving cold front produced heavy rain and flash flooding across portions of the region. This is the same front that caused flash flooding the day prior.
Flash Flood — Jul 8, 2025
A cold front produced heavy rain and flash flooding across portions of the region.
Flash Flood — Jul 7, 2025
Low pressure, Post-Tropical Cyclone Chantal, induced heavy rain and flash flooding across portions of the region.
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 Chester 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 Chester 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.