Enter any address in Mercer County, Pennsylvania to see its FEMA flood zone
Flash flooding from thunderstorms is the dominant flood character in Mercer County. Between 1993 and 2023, the NOAA Storm Events Database recorded 82 flash flood events and 23 flood events. For example, thunderstorms trained along a boundary on September 4, 2022, causing road flooding, and a warm front passage on July 20, 2023, resulted in isolated urban flash flooding.
National Flood Insurance Program (NFIP) data shows a range of claim severities. Zone A, which has no base flood elevation defined, accounted for 50 claims with an average payout of $5,770 and an average water depth of 1.3 feet. Zone X_SHADED, representing areas with moderate flood risk, had fewer claims (11) but a significantly higher average payout of $18,806 and an average water depth of 6.2 feet. Homeowners in areas designated as Zone A, or those without a defined base flood elevation, should pay the most attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
22 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Mercer County, Pennsylvania has recorded 105 flood-related events since 1996 according to NOAA's Storm Events Database, including 82 flash floods and 23 river or area floods. The county has received 13 federal disaster declarations, 3 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 |
| Hurricane Sandy | Hurricane | Oct 26, 2012 |
| 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 | Jul 21, 2003 |
| Severe Storms And Flooding | Flood | Jan 19, 1996 |
| Severe Snowfall & Winter Storm | Snowstorm | Mar 13, 1993 |
| Severe Storms, High Winds & Tornadoes | Tornado | May 31, 1985 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | Jul 16, 2025 | 0.00K |
| Flash Flood | Jul 20, 2023 | 5.00K |
| Flood | Nov 11, 2022 | 0.00K |
| Flash Flood | Sep 4, 2022 | 0.00K |
| Flash Flood | Jul 16, 2021 | 10.00K |
| Flash Flood | Jul 16, 2021 | 50.00K |
| Flash Flood | Aug 13, 2021 | 0.00K |
| Flash Flood | Jul 20, 2019 | 5.00K |
| Flash Flood | Aug 18, 2019 | 0.00K |
| Flood | Jun 5, 2019 | 0.00K |
Flash Flood — Jul 16, 2025
A crossing cold front and weak shortwave passage spawned of scattered clusters of thunderstorms in an environment with 1500-2000 J/kg MLCAPE, >1000 J/Kg DCAPE, and weak deep layer shear. Some storms were severe with damaging wind.
Flash Flood — Jul 20, 2023
The passage of a warm front during the morning of July 20th provided a moist and unstable air mass. A strong, progressive upper trough tracked southeastward from the Great Lakes, with an associated cold front crossing during the evening hours. Mixed-layer CAPE of up to 2500 J/kg, strong deep shear, and steep low and mid-level lapse rates were supportive of severe weather. Widespread reports o...
Flood — Nov 11, 2022
The remnants of Hurricane Nicole, in combination with a Great Lakes cold front, lead to heavy precipitation totals across the region. Rainfall totals of 1.5 to 3.5 inches, with localized higher totals, were common across the region. Most of the rainfall falling during the November 11th calendar day. However, flooding was limited to very isolated instances. This was due to the quite dry antec...
Flash Flood — Sep 4, 2022
Thunderstorms trained along a nearly stationary boundary crossing into northwest Pennsylvania during the evening hours of September 4th, taking advantage of a moisture-laden air mass. Instances of road flooding were observed in Mercer and Venango Counties.
Flash Flood — Jul 16, 2021
On July 16th, a weak positively-tilted trough tracked from the Mississippi River Valley towards the Great Lakes today, while a surface front slowly sagged south from Lake Erie. Diurnal heating in an air mass with rich moisture plus increasing jet support yielded numerous thunderstorms, mainly favoring eastern Ohio and northwest Pennsylvania. Differential heating on the southern fringe of a thic...
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 Mercer 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 Mercer 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.