Enter any address in Frederick County, Maryland to see its FEMA flood zone
Flash flooding from slow-moving thunderstorms is a significant flood hazard in Frederick County. Over the past 30 years, NOAA Storm Events data shows 219 flood events and 92 flash flood events, with flash flooding resulting in 6 reported fatalities. For example, heavy rainfall from slow-moving storms caused flash flooding on May 14, 2025, with localized totals of four to eight inches. Similarly, on July 31, 2025, training thunderstorms produced scattered flash flooding with rainfall amounts up to six inches in some areas.
NFIP claims data indicates that properties in Zone A experienced the most claims, with an average payout of $9,721 and an average water depth of 2.4 feet. Properties in Zone X_UNSHADED also saw substantial claims, averaging $11,681 with 1.0 foot of water depth. Homeowners in these zones, 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.
138 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Frederick County, Maryland has recorded 313 flood-related events since 1996 according to NOAA's Storm Events Database, including 92 flash floods and 219 river or area floods. The county has received 23 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 (1971–2026)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Severe Winter Storm | Winter Storm | Jan 23, 2026 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms And Flooding | Severe Storm | May 15, 2018 |
| Severe Winter Storm And Snowstorm | Snowstorm | Jan 22, 2016 |
| Hurricane Sandy | Hurricane | Oct 26, 2012 |
| Hurricane Irene | Hurricane | Aug 26, 2011 |
| Severe Winter Storms And Snowstorms | Snowstorm | Feb 5, 2010 |
| Hurricane Katrina Evacuation | Hurricane | Aug 29, 2005 |
| Hurricane Isabel | Hurricane | Sep 18, 2003 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | Jul 31, 2025 | 0.00K |
| Flood | May 14, 2025 | 0.00K |
| Flash Flood | May 5, 2025 | 0.00K |
| Flash Flood | Aug 29, 2024 | 0.00K |
| Flood | Dec 23, 2022 | 0.00K |
| Flood | Dec 22, 2022 | 0.00K |
| Flood | May 7, 2022 | 0.00K |
| Flood | May 6, 2022 | 0.00K |
| Flood | May 26, 2021 | 0.00K |
| Flood | Sep 23, 2021 | 0.00K |
Flash Flood — Jul 31, 2025
A slow moving cold front combined with a highly unstable atmosphere along with tropical moisture to produce slow moving thunderstorms with heavy rainfall. Some of these storms trained over the same areas, resulting in scattered to numerous instances of flash flooding. Total rainfall amounts in areas with flash flooding averaged two to four inches, though some localized amounts up to six inches ...
Flood — May 14, 2025
A slow moving closed upper level low originating from the Gulf of America brought anomalous moisture into the area. A long duration period of rain ensued, with rain rates exceeding two inches an hour during the afternoon of May 13th. The slow moving storms coupled with training led to localized rainfall totals of four to eight inches across western Maryland, with lesser amounts of two to four i...
Flash Flood — May 5, 2025
An area of upper level low pressure brought repetitive rounds of slow moving thunderstorms to parts of central Maryland. The heaviest rain fell across Frederick County, Maryland where to two to four inches of rain were observed.
Flash Flood — Aug 29, 2024
Heavy rainfall along a stalled boundary led to instances of flash flooding.
Flood — Dec 23, 2022
A coastal low pressure system interacted with a warm front resulting in a widespread two to three inches of rain with localized amounts up to four inches. This resulted in road closures due to high water and small streams overflowing their banks. River flooding also occurred.
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 Frederick County, Maryland:
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 Frederick County, Maryland 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.