St. Clair River
The National Weather Service’s marine forecast for St. Clair River, from NWS Detroit/Pontiac, MI.
St. Clair River on the map
The zone and the zones around it, tinted where a marine warning or advisory is in force. Tap a neighboring zone to open its forecast.
Now
The nearest stations reporting each, as of Sat, Sep 26, 1:00 AM EDT.
- Wind
- NNE 16 kt at 45147
- Waves
- 1.3 ft at 3 s at 45147
- Water
- 64°F at AGCM4
Alerts in force
No marine warning or advisory is in force for this zone.
What is normally issued here: in the past year NWS Detroit/Pontiac, MI issued 24 Special Marine Warnings, 8 Severe Thunderstorm Watches, 2 Tornado Watches for this zone.
The forecast
No marine forecast product the National Weather Service issues now names this zone.
NWS Detroit/Pontiac, MI may cover it in a product for the waters around it, or only in season. The zone at the NWS.
Buoys and stations nearby
The latest report from each station within reach of the zone, nearest first. Distances in nautical miles from the middle of the zone.
| Station | Distance | Wind | Waves | Water | Air | Pressure | Reported |
|---|---|---|---|---|---|---|---|
| AGCM4 9014070 - Algonac, MI | 6 nm | 64°F | 1023.9 hPa | Sat, Sep 26, 12:48 AM EDT | |||
| 45147 Lake St Clair | 8 nm | NNE 16 kt | 1.3 ft at 3 s | 63°F | 60°F | 1023.7 hPa | Sat, Sep 26, 1:00 AM EDT |
| CLSM4 St. Clair Shores, MI | 12 nm | N 7 kt, gusts 9 | 57°F | 1025.1 hPa | Sat, Sep 26, 1:00 AM EDT | ||
| FTGM4 9014098 - Fort Gratiot, MI | 28 nm | NE 16 kt, gusts 19 | 1024.2 hPa | Sat, Sep 26, 12:48 AM EDT | |||
| 45209 Lakeport Buoy, MI | 36 nm | ENE 14 kt, gusts 17 | 3.0 ft at 4 s from NNE | 65°F | 61°F | Sat, Sep 26, 1:10 AM EDT | |
| 45005 WEST ERIE - 16 NM NW of Lorain, OH | 54 nm | NE 10 kt, gusts 14 | 63°F | 1023.5 hPa | Sat, Sep 26, 1:00 AM EDT |
The past year
Warnings, watches and advisories the National Weather Service issued for this zone over the past 12 months, from the Iowa Environmental Mesonet’s archive.
| Product | Issued | Most recent |
|---|---|---|
| Special Marine Warning | 24 | Thu, Sep 3, 2026, 2:26 PM EDT |
| Severe Thunderstorm Watch | 8 | Thu, Sep 3, 2026, 2:00 PM EDT |
| Tornado Watch | 2 | Thu, Jun 11, 2026, 10:24 PM EDT |
What this means
Marine forecasts give wind in knots (1 knot is 1.15 mph) and seas in feet, except the high seas forecasts, which give seas in meters. Seas are the significant wave height, the average of the highest third of the waves; individual waves may be more than twice that. On the Great Lakes the forecast gives waves, not seas. "Wave Detail" splits the seas into the wind waves and each swell, with its direction and period.
Each coastal office writes a Coastal Waters Forecast for the bays, sounds and ocean out to 20 to 60 nautical miles, or on the Great Lakes a Nearshore Marine Forecast within 5 nautical miles of shore; the Open Lakes Forecast covers the rest of each lake. The Ocean Prediction Center and the National Hurricane Center write the Offshore Waters Forecasts out to about 250 nautical miles, and the High Seas Forecasts beyond. Forecasts are issued at least twice a day and updated when they go wrong.
- Small Craft Advisory
- Winds or conditions hazardous to small boats. The thresholds are set by each NWS region: typically sustained winds or frequent gusts of 20 to 25 knots up to 33 knots, and seas of 5 to 7 feet or more.
- Gale Warning
- Sustained winds or frequent gusts of 34 to 47 knots, not from a tropical cyclone.
- Storm Warning
- Sustained winds or frequent gusts of 48 to 63 knots, not from a tropical cyclone.
- Hurricane Force Wind Warning
- Sustained winds or frequent gusts of 64 knots or more, not from a tropical cyclone.
- Special Marine Warning
- A thunderstorm or squall over the water with winds or gusts of 34 knots or more, hail of 3/4 inch or more, or a waterspout, for up to two hours.
- Hazardous Seas Warning
- Wave heights or steepness at or above the office’s warning threshold, when the wind alone does not warrant a warning.
- Heavy Freezing Spray Warning
- Spray freezing on a vessel at 2 cm (3/4 inch) an hour or more.
- Tropical Storm and Hurricane Warnings
- Tropical storm (34 to 63 knots) or hurricane (64 knots or more) conditions expected within 36 hours. Watches: possible within 48 hours.
Nearby
- Lake St. Clair Open Lake (U.S. Portion)
- Detroit River
- Port Sanilac to Port Huron MI
- Lake Huron from Port Sanilac to Port Huron 5NM Off Shore to US/Canadian border
- Detroit River Lt. to Maumee Bay OH to Reno Beach OH beyond 5NM offshoreline to US-Canadian border
- Michigan Waters of Lake Erie from Detroit River to North Cape MI
- Reno Beach to The Islands OH beyond 5NM off shoreline to US-Canadian border
- Vermilion to Avon Point OH beyond 5 nm off shoreline to US-Canadian border
- Maumee Bay to Reno Beach OH
- Reno Beach to The Islands OH
Open the live map with marine zones and buoysThe hour-by-hour forecast for the middle of the zoneMacomb County Area BeachesSt. Clair County Area BeachesWayne County Area BeachesEvery Great Lakes zone
Sources
The zone at the NWS. Buoy reports from the National Data Buoy Center. Past products from the Iowa Environmental Mesonet. Zone outlines from the NWS marine and offshore zone boundaries. Warnings and advisories from the NWS API, read 05:36 UTC. All public domain, from the National Weather Service.