Grand Marais, MI (GRMM4) — Live Marine Conditions & Buoy Data
NOAA station GRMM4, Grand Marais, MI, reports real-time marine conditions from 46.684°N, 85.972°W in Lake Superior (Michigan). Readings refresh roughly every 10 minutes, and Big Buoy adds a solunar table and a multi-day weather outlook for the area.
Current conditions at Grand Marais, MI
As of August 21, 2026 at 19:50 UTC, Grand Marais, MI (GRMM4) is reporting wind from the SSW at 18 mph gusting 24 mph.
- Wind
- SSW 18 mph (gust 24)
Observed August 21, 2026 at 19:50 UTC from NOAA NDBC station GRMM4. Readings update about every 10 minutes.
What NOAA buoy GRMM4 measures
As a NOAA meteorological station, GRMM4 reports wind speed, gusts and direction, barometric pressure, air and water temperature, and — where wave sensors are fitted — significant wave height, swell period, and wave direction.
What to watch in Lake Superior
Lake Superior is the coldest, deepest, and largest of the Great Lakes, with enough open water and fetch to build true offshore seas. Water stays cold most of the year and storms move through fast, so a sustained blow can raise steep, short-period waves with little warning — read wind, fetch, and sea state together before heading out.
Frequently asked questions
- Where is NOAA buoy GRMM4 located?
- Grand Marais, MI (GRMM4) reports from 46.684°N, 85.972°W in Lake Superior (Michigan).
- How often is NOAA buoy GRMM4 updated?
- Station GRMM4 typically reports new observations about every 10 minutes. Big Buoy refreshes continuously so you always see the latest readings, alongside a solunar table for the area.
- What does NOAA buoy GRMM4 measure?
- Big Buoy shows wind, barometric pressure, air and water temperature, and wave height and period where available for Grand Marais, MI, plus solunar peak windows and a multi-day weather outlook.
- Is Big Buoy free to use?
- Yes. Live data for Grand Marais, MI and every other NOAA buoy is free with no account required. Big Buoy Pro adds the Wind Tab, the Depth Chart, satellite overlays (sea surface temp, chlorophyll, currents), 16-day forecasts, and forecast model switching.