Winthrop Harbor Buoy, IL (45187) — Live Marine Conditions & Buoy Data
NOAA station 45187, Winthrop Harbor Buoy, IL, reports real-time marine conditions from 42.491°N, 87.779°W in Lake Michigan (Illinois). Readings refresh roughly every 10 minutes, and Big Buoy adds a solunar table and a multi-day weather outlook for the area.
Lake Michigan Marine Conditions — Winthrop Harbor Buoy, IL is one of several stations in Lake Michigan. See live buoy data and solunar for the whole area.
Current conditions at Winthrop Harbor Buoy, IL
As of October 19, 2026 at 19:40 UTC, Winthrop Harbor Buoy, IL (45187) is reporting water temperature 57°F, air temperature 58°F, wind at 9 mph gusting 13 mph, and barometric pressure 30.29 inHg.
- Water temperature
- 57°F
- Air temperature
- 58°F
- Wind
- 9 mph (gust 13)
- Barometric pressure
- 30.29 inHg
Observed October 19, 2026 at 19:40 UTC from NOAA NDBC station 45187. Readings update about every 10 minutes.
What NOAA buoy 45187 measures
As a NOAA meteorological station, 45187 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 Michigan
Lake Michigan’s long north-south axis lets a sustained northerly or southerly wind build large, steep seas over its full fetch, sometimes within hours. Summer stratification is sharp and wind-driven upwelling can swing nearshore water temperature 15–20°F in a day, so watch wind direction and buoy temperatures together.
Frequently asked questions
- What is the water temperature at Winthrop Harbor Buoy?
- Sea surface temperature at Winthrop Harbor Buoy was 57°F. Measured October 19, 2026 at 19:40 UTC by NOAA station 45187 (Winthrop Harbor Buoy, IL). NDBC measures this near the surface, at a depth that varies by station.
- What is the air temperature at Winthrop Harbor Buoy?
- Air temperature at Winthrop Harbor Buoy was 58°F. Measured October 19, 2026 at 19:40 UTC by NOAA station 45187 (Winthrop Harbor Buoy, IL).
- What is the wind doing at Winthrop Harbor Buoy?
- Wind at Winthrop Harbor Buoy was at 9 mph, with peak gusts to 13 mph. Measured October 19, 2026 at 19:40 UTC by NOAA station 45187 (Winthrop Harbor Buoy, IL). NDBC records wind at the station’s anemometer height, which is not the 10 m height used in marine forecasts.
- What is the barometric pressure at Winthrop Harbor Buoy?
- Sea-level pressure at Winthrop Harbor Buoy was 30.29 inHg (1025.8 hPa). Measured October 19, 2026 at 19:40 UTC by NOAA station 45187 (Winthrop Harbor Buoy, IL). NDBC reports pressure reduced to sea level rather than the raw reading at the station.
- Where is NOAA buoy 45187 located?
- Winthrop Harbor Buoy, IL (45187) reports from 42.491°N, 87.779°W in Lake Michigan (Illinois).
- How often is NOAA buoy 45187 updated?
- Station 45187 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 45187 measure?
- Big Buoy shows wind, barometric pressure, air and water temperature, and wave height and period where available for Winthrop Harbor Buoy, IL, plus solunar peak windows and a multi-day weather outlook.
- Is Big Buoy free to use?
- Yes. Live data for Winthrop Harbor Buoy, IL 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.