FloodZoneMap.org

Union County, Pennsylvania Flood Zones

Check an Address in Union County

Enter any address in Union County, Pennsylvania to see its FEMA flood zone

The Flooding Character of Union County

Flash flooding from thunderstorms is the dominant flood character in Union County, PA. Between 2003 and 2023, NOAA Storm Events data recorded 24 flood events and 20 flash flood events. For example, on August 7, 2023, severe weather produced widespread wind damage and tornadoes across south-central Pennsylvania, contributing to flooding in the region.

NFIP claims data shows that properties in Zone A have experienced the most claims, with 616 claims averaging $13,442 and an average water depth of 4.2 feet. Properties in Zone X and Zone X_Shaded also show significant claim activity, with average payouts exceeding $11,000 and average water depths of 2.5 and 4.2 feet, respectively.

Homeowners in Zone A, as well as those in Zones X and X_Shaded, should pay particular attention to flood risk. Properties located in these zones have historically experienced substantial flood damage and higher water depths.

Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.

Read First-Hand Flood Stories from Union County

8 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.

Read Pennsylvania flood stories →

Flood Risk Data for Union County

Union County, Pennsylvania has recorded 45 flood-related events since 1996 according to NOAA's Storm Events Database, including 20 flash floods and 24 river or area floods. The county has received 18 federal disaster declarations, 6 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.

Union County Disaster History

FEMA Disaster Declarations (1972–2024)

Disaster Declarations
18
Flood/Coastal Disasters
6
Hurricane Disasters
1
Latest Disaster
Tropical Storm Debby (2024-08-09)

Source: OpenFEMA Disaster Declarations Summaries.

Recent Disaster Declarations in Union County

DeclarationTypeDate
Tropical Storm DebbyTropical StormAug 9, 2024
Covid-19BiologicalJan 20, 2020
Covid-19 PandemicBiologicalJan 20, 2020
Hurricane SandyHurricaneOct 26, 2012
Remnants Of Tropical Storm LeeFloodSep 3, 2011
Tropical Storm LeeFloodSep 3, 2011
Hurricane KatrinaHurricaneAug 29, 2005
Tropical Depression IvanHurricaneSep 17, 2004
Severe Storms And Flooding Associated With Tropical Depression FrancesSevere StormSep 8, 2004
SnowSevere StormFeb 14, 2003

Recorded Flood Events in Union County

NOAA Storm Events Database (1996–2025)

Total Flood Events
45
River/Area Floods
24
Flash Floods
20
Hurricanes/Tropical Storms
1
Total Property Damage
$11.0M

Source: NOAA National Weather Service Storm Events Database.

Recent Flood Events in Union County

TypeDateDamage
FloodAug 7, 20230.00K
FloodAug 7, 202325.00K
Flash FloodFeb 4, 20220.00K
FloodMar 12, 20150.00K
FloodMay 16, 20140.00K
Flash FloodMay 8, 20130.00K
Flash FloodSep 28, 20110.00K
FloodMar 10, 20110.00K
FloodSep 7, 2011800.00K
FloodMar 6, 20110.00K

Union County Flood History

Flood — Aug 7, 2023

High CAPE (>2500 J/kg) and strong speed and directional shear contributed to a significant severe weather episode across south-central Pennsylvania during the afternoon and evening of August 7, 2023. Of note, a significant bow echo produced widespread wind damage and a trio of weak (EF0-EF1) tornadoes across southern York and Lancaster Counties.

Flash Flood — Feb 4, 2022

Warm temperatures and rainfall resulted in an ice jam on Penns Creek in the Millmont area of Union County.

Flood — Mar 12, 2015

With the milder temperatures beginning on March 11th���some minor flooding was reported across the HSA, mainly due to ice jams.||Later on Thursday March 12th an ice jam was reported by the public along Penns Creek upstream from the Route 104 Bridge, and a flood advisory was issued for parts of Union and Snyder Counties.||On March 13th and 14th temperatures again warmed along with a period...

Flood — May 16, 2014

Deep southerly flow transported a plume of seasonably high moisture into the region along a slow-moving, north-south oriented cold front. This favorable heavy rain pattern produced a stripe of 2.5-5.0 inches of rainfall from the northern Blue Ridge into the north-central mountains of Pennsylvania. Widespread small stream flooding and multiple road closures were reported with five river forecast...

Flash Flood — May 8, 2013

Training bands of locally heavy rain impacted parts of the middle Susquehanna Valley during the late morning and early afternoon. A deep east-southeast flow from the Atlantic pulled high moisture into the region around an upper-level low rotating northward from MD/VA. Rainfall rates of 1-2/hour were common with localized rainfall rates as high as 4/hour. Several locations around the Lewisburg, ...

Source: NOAA National Weather Service Storm Events Database.

Union County NFIP Flood Insurance Claims

Total Claims Filed
764
Total Paid Out
$9.5M
Avg Claim
$14,505
Avg Water Depth
11.6 ft

Claims by Flood Zone

A Zones (High Risk)
616
X Shaded (500-yr)
40
X Unshaded (Low)
5

Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).

Flood Zone Types in Union County

FEMA assigns flood zone designations to areas in Union 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.

View all flood zone types →

Flood Insurance in Union County

Properties in Union 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.