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St. Mary's County weather alerts

1 active alert for St. Mary's County, Maryland right now: a Coastal Flood Advisory.

41 in the last 30 days 49 in 12 months (since Aug 30) most common: Coastal Flood Advisory Get alerts on your phone →

Active alerts for St. Mary's County

Refreshed every few minutes; times in EDT.

Minor Expected

Coastal Flood Advisory

Issued Wed, Oct 21, 10:11 PM EDT by NWS Baltimore MD/Washington DC Until Thu, Oct 22, 3:00 PM EDT (in 14 hr)

Area: St. Marys

* WHAT...Up to two feet of inundation above ground level expected in low lying areas due to tidal flooding. * WHERE...Shoreline in St. Marys County. * WHEN...Until 3 PM EDT Thursday, especially around the time of high tide. * IMPACTS...At 3.5 feet, water covers roads on Saint George Island, is in yards, and is approaching structures. To the east, inundati...

What it means: Minor coastal flooding is expected, usually around high tide. Expect water on low-lying roads near the shore.

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Where

St. Mary's County on the map

Alert polygons are NWS's own. Forecast Bar's radar shows the same warnings over live precipitation, with future radar and lightning. See the radar.

Last 30 days

Recent alerts for St. Mary's County

AlertIssuedEndedIssued by
Coastal Flood Advisory Oct 21, 6:12 PM 3:00 PM Baltimore MD/Washington DC
Severe Thunderstorm Watch Oct 16, 6:36 PM Oct 16, 8:00 PM Baltimore MD/Washington DC
Severe Thunderstorm Watch Oct 16, 5:09 PM Oct 16, 8:00 PM Baltimore MD/Washington DC
Severe Thunderstorm Watch Oct 16, 4:37 PM Oct 16, 8:00 PM Baltimore MD/Washington DC
Severe Thunderstorm Watch Oct 16, 4:04 PM Oct 16, 8:00 PM Baltimore MD/Washington DC
Severe Thunderstorm Watch Oct 16, 2:14 PM Oct 16, 8:00 PM Baltimore MD/Washington DC
Severe Thunderstorm Watch Oct 16, 1:25 PM Oct 16, 8:00 PM Baltimore MD/Washington DC
Special Weather Statement Oct 5, 6:39 AM Oct 5, 9:00 AM Baltimore MD/Washington DC
Special Weather Statement Oct 5, 4:06 AM Oct 5, 7:00 AM Baltimore MD/Washington DC
Special Weather Statement Oct 5, 2:17 AM Oct 5, 7:00 AM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 27, 2:24 PM Sep 27, 6:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 27, 9:25 AM Sep 27, 6:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 27, 3:11 AM Sep 27, 6:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 26, 10:56 PM Sep 27, 6:00 PM Baltimore MD/Washington DC
Coastal Flood Warning Sep 26, 2:50 PM Sep 27, 6:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 26, 2:50 PM Sep 26, 11:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 26, 8:36 AM Sep 27, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 26, 3:18 AM Sep 27, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 25, 7:05 PM Sep 27, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 25, 4:43 PM Sep 27, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 25, 2:38 PM Sep 27, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 25, 8:28 AM Sep 26, 5:00 AM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 25, 2:59 AM Sep 26, 5:00 AM Baltimore MD/Washington DC
Coastal Flood Warning Sep 24, 7:23 PM Sep 25, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Warning Sep 24, 2:34 PM Sep 25, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Warning Sep 24, 10:47 AM Sep 25, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Warning Sep 24, 3:10 AM Sep 25, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Warning Sep 23, 10:41 PM Sep 25, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Warning Sep 23, 3:08 PM Sep 25, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Watch Sep 23, 8:42 AM Sep 25, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Warning Sep 23, 8:42 AM Sep 24, 4:00 AM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 23, 8:42 AM Sep 23, 6:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 23, 3:00 AM Sep 23, 8:00 PM Baltimore MD/Washington DC
Coastal Flood Watch Sep 23, 3:00 AM Sep 25, 5:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 22, 10:10 PM Sep 23, 8:00 PM Baltimore MD/Washington DC
Coastal Flood Watch Sep 22, 10:10 PM Sep 25, 12:00 PM Baltimore MD/Washington DC
Coastal Flood Watch Sep 22, 2:53 PM Sep 25, 12:00 PM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 22, 2:53 PM Sep 23, 8:00 PM Baltimore MD/Washington DC
Coastal Flood Watch Sep 22, 9:35 AM Sep 24, 11:00 AM Baltimore MD/Washington DC
Coastal Flood Advisory Sep 22, 9:35 AM Sep 23, 8:00 PM Baltimore MD/Washington DC

Pattern

What St. Mary's County gets alerted for

Every alert that named St. Mary's County in the last 12 months, by type. Records begin August 30, 2026, so this fills in over the year.

Coastal Flood Advisory
20
Severe Thunderstorm Watch
12
Coastal Flood Warning
8
Coastal Flood Watch
6
Special Weather Statement
3

Plain English

What these alerts mean

A warning means the hazard is happening or about to; a watch means conditions favour it; an advisory is a lesser hazard still worth planning around.

Coastal Flood Advisory

Minor coastal flooding is expected, usually around high tide. Expect water on low-lying roads near the shore.

Severe Thunderstorm Watch

Conditions are favourable for severe thunderstorms with large hail or damaging wind. Keep an eye on the sky and on warnings.

Special Weather Statement

A heads-up about conditions that do not meet warning or advisory criteria but still deserve attention, such as a strong storm, patchy fog or a brief burst of snow.

Coastal Flood Warning

Significant coastal flooding is occurring or imminent, typically at high tide. Move away from low-lying shoreline areas.

Coastal Flood Watch

Significant coastal flooding is possible. Prepare to protect property near the shore.

Nearby

Alerts near St. Mary's County

Neighbouring counties in Maryland

Calvert County1 Charles County1 Dorchester County1 All of Maryland →

Questions

About St. Mary's County alerts

How do I get St. Mary's County weather alerts on my iPhone?

Install Forecast Bar, add St. Mary's County as a location, and turn on severe weather alerts. Every NWS warning, watch and advisory for St. Mary's County then arrives as a push notification at the moment of issue, with Critical Alerts available for the most dangerous warnings. Forecast Bar also runs on iPad, Apple Watch, Mac and Apple TV.

Where do these alerts come from?

From the National Weather Service alert feed (api.weather.gov). NWS issues alerts by county and by forecast zone; this page lists every product that names St. Mary's County. Forecast Bar checks the feed continuously and this page refreshes within a few minutes of a change.

What is the difference between a watch, a warning and an advisory?

A warning means the hazard is occurring, imminent or very likely: act now. A watch means conditions are favourable for it to develop: prepare and stay informed. An advisory covers a hazard that is less serious than a warning but can still cause real inconvenience or danger if you are not ready for it.

Can I get this data as JSON?

Yes. /weather-alerts/md/st-mary-s-county.json returns the active alerts, the last 30 days and the 12-month counts for St. Mary's County, refreshed every minute. Please cache responses and credit National Weather Service as the source.

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