Enter any address in St. Mary's County, Maryland to see its FEMA flood zone
St. Mary's County experiences a mix of flood types, with coastal flooding and general flooding being the most frequent over the last 30 years. Recent coastal flood events occurred in January, March, April, and May of 2024, driven by strong southerly winds, high astronomical tides, and onshore flow. These events have raised water levels along the Chesapeake Bay shoreline.
National Flood Insurance Program (NFIP) data shows a significant number of claims in Zone A, with an average payout of $18,569 for an average water depth of 1.6 feet. While Zone X has fewer claims, some have resulted in higher average payouts and deeper water, with an average depth of 3.9 feet in Zone X and 2.4 feet in Zone X_SHADED.
Homeowners with properties along the coast, near tidal rivers, or in areas designated as Zone A or X should pay particular attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
51 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
St. Mary's County, Maryland has recorded 248 flood-related events since 1996 according to NOAA's Storm Events Database, including 72 flash floods and 86 river or area floods. The county has received 18 federal disaster declarations. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1977–2026)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Severe Winter Storm | Winter Storm | Jan 23, 2026 |
| Tropical Storm Isaias | Hurricane | Aug 3, 2020 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Hurricane Sandy | Hurricane | Oct 26, 2012 |
| Severe Storms And Straight-line Winds | Severe Storm | Jun 29, 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 |
|---|---|---|
| Coastal Flood | Apr 19, 2024 | 0.00K |
| Coastal Flood | Apr 12, 2024 | 0.00K |
| Coastal Flood | May 11, 2024 | 0.00K |
| Coastal Flood | Mar 9, 2024 | 0.00K |
| Coastal Flood | Jan 9, 2024 | 0.00K |
| Coastal Flood | Feb 6, 2024 | 0.00K |
| Coastal Flood | Apr 3, 2024 | 0.00K |
| Coastal Flood | Apr 30, 2023 | 0.00K |
| Coastal Flood | Sep 27, 2023 | 0.00K |
| Coastal Flood | Sep 23, 2023 | 0.00K |
Coastal Flood — Apr 19, 2024
Easterly onshore flow followed by southerly winds resulted in moderate coastal flooding at Annapolis and St. Mary's County.
Coastal Flood — Apr 12, 2024
Strong southerly flow ahead of a low pressure system resulted in moderate coastal flooding at Annapolis and Straits Point.
Coastal Flood — May 11, 2024
Elevated water levels due to onshore flow resulted in moderate coastal flooding at Straits Point MD and Annapolis for multiple high tide cycles.
Coastal Flood — Mar 9, 2024
A moderate onshore flow combined with high astronomical tides due to a New Moon resulted in moderate coastal flood event at Annapolis and St. Mary's Counties.
Coastal Flood — Jan 9, 2024
A strong area of low pressure tracked from the mid MS River Valley on Jan 9th to the Northeast U.S. Jan 10th. A very strong pressure gradient ahead of the low pressure center resulted in a long period of strong southerly winds gusting up to 55 mph that raised water levels to major levels at several locations along the western shore of the Chesapeake Bay.
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 St. Mary's 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 St. Mary's 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.