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    Portage Lake scenic landscape
    Home>Lakes>Portage Lake>Water Level & Temperature
    Live Hydrology TelemetryLast updated: Oct 11, 2026 • 12:02 AM
    ← Lake Dashboard

    Portage Lake Water Level & Water Temperature

    Michigan

    The linked gauge for Portage Lake reported 579.32 ft (relative to IGLD 1985) at its latest stored observation on Oct 11, 2026, on a falling 30-day trend (-0.07 ft).

    Stage / Gage579.32 ft
    30-Day Trend-0.07 ft
    BenchmarkSurvey Baseline
    Surface Temp56.1°F
    Monitoring Station
    USGS NWIS
    Ludington, MI
    Sensor ID9087023
    Distance30.4 mi away
    Vertical DatumIGLD 1985
    Photo: Annacecchini • CC BY-SA 4.0 via Wikimedia Commons
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    Latest Gage HeightWater Level
    579.32FT GAGE

    Local gage height: 579.32 ft

    Observed Oct 11, 12:00 AMHistory & Readings ↓
    30-Day TrendWater Level
    Falling-0.07 FT

    -0.07 ft net change over past 30 days

    30-Day WindowHistorical Trajectory
    Surface AreaWater Level
    2,110AC

    Verified freshwater recreation waterbody

    Basin MetricSurvey Reference
    Water TemperatureSensor Reading
    56.1°F

    Brisk (50–60°F) · Cold shock risk · Wetsuit recommended

    Linked monitoring sensor

    Water Level

    Last 29 Days
    Surface elevation
    579.3 ft
    ↓ -0.1 ft (7 days)
    579.5579578.5578577.5Sep 12Sep 19Sep 27Oct 4Oct 11579.3 ft
    Provisional NOAA CO-OPS reading
    Daily History Table ↓

    Water Temperature (Surface)

    Surface temperature (Measured lake temperature)
    56.1°F
    Measured

    L MANISTEE R AT NINE MILE BRIDGE NR FREESOIL, MI · Oct 10, 11:30 PM UTC

    7570645953Sep 29Oct 2Sep 29Oct 2Oct 556.1°F
    Historical daily
    7-Day forecast
    Forecast uncertainty
    Temperature Guide ↓

    30-Day Gage Height History

    Gage height in feet relative to IGLD 1985 · Daily observations
    30d Range578.96 – 579.41 ft
    579.41 ft579.19 ft578.96 ftSep 11Sep 26Oct 11

    Recent Gage Height Readings

    Most recent linked-gauge observations, newest first. Gage height in ft relative to IGLD 1985.
    Observation DateGage height (ft)24h ChangeApproval Status
    Sun, Oct 11, 2026579.26+0.11 ftProvisional
    Sat, Oct 10, 2026579.150.00 ftProvisional
    Sat, Oct 10, 2026579.15+0.19 ftProvisional
    Fri, Oct 9, 2026578.960.00 ftProvisional
    Fri, Oct 9, 2026578.96-0.01 ftProvisional
    Thu, Oct 8, 2026578.970.00 ftProvisional
    Thu, Oct 8, 2026578.97-0.11 ftProvisional
    Wed, Oct 7, 2026579.080.00 ftProvisional
    Wed, Oct 7, 2026579.08+0.04 ftProvisional
    Tue, Oct 6, 2026579.040.00 ftProvisional
    Tue, Oct 6, 2026579.04+0.06 ftProvisional
    Mon, Oct 5, 2026578.970.00 ftProvisional
    Mon, Oct 5, 2026578.97-0.23 ftProvisional
    Sun, Oct 4, 2026579.20—Provisional

    Portage Lake Water Temperature & Seasonal Thermal Guide

    Seasonal thermal layers, limnology dynamics, and temperature benchmarks.
    Current verified surface temperature: 56.1°F(Brisk (50–60°F))
    Linked monitoring sensor
    Summer Peak (Jun–Aug)68°F – 78°FPrime open water swimming, tubing, and shoreline wading.
    Fall Shoulder (Sep–Nov)56°F – 66°FCool water; active fall bass, trout, and walleye feeding transition.
    Spring Pre-Spawn (Apr–May)48°F – 58°FCold shock hazard; wetsuits recommended and USCG PFD required.
    Winter Min (Dec–Mar)34°F – 44°FSevere immersion hazard; possible surface freezing or ice cover.
    Limnological Note: In temperate freshwater lakes, the epilimnion (surface layer) warms quickly on sunny afternoons, while water below 15–20 feet remains 10–20°F cooler.

    Portage Lake Swimming & Immersion Suitability

    Real-time open water swimming readiness calculated from verified water temperature (56.1°F), cold shock hazards, and local atmospheric conditions for Portage Lake
    Forecast & Solar Times →
    29/ 100
    Very Poor / Avoid
    Swimming Readiness:

    Current index calculated from verified local atmospheric, hydrographic & alert inputs.

    Very Poor / Avoid for swimming (29/100), from 5 available inputs. Supporting this: No active official alerts for this lake. 1% chance of precipitation. Working against it: Measured water temperature 53°F from a representative gauge 15.7 mi away. Provisional data. Immersion shock hazard: water below 55°F poses severe cold shock and rapid hypothermia risk. Water temperature is 53°F (below 55°F). Severe cold shock and hypothermia hazard upon immersion. Confidence is moderate (75%) because some inputs are unavailable or older than ideal.

    Scoring Factors & Telemetry Inputs
    Storms and alertsNo alerts100% score
    Air temperature68°F65% score
    Water temperature53°F17% score
    Wind10 mph S88% score
    Precipitation chance1%99% score

    Portage Lake Telemetry & Sensor Provenance

    Physical in-situ monitoring equipment, benchmarks & sensor specifications
    Monitoring StationLudington, MI
    Station IdentifierStation #9087023
    Coverage TypeRepresentative sensor (30.4 mi from lake)
    Vertical DatumIGLD 1985
    Sensor Coordinates43.9474° N, 86.4415° W
    Parameters TrackedElevation (Datum), Water Temperature

    Frequently Asked Questions About Portage Lake Water

    Common questions about water levels, elevation, and swimming temperature
    What is the current water level at Portage Lake?+
    The linked gauge's latest stored gage height for Portage Lake is 579.32 ft relative to IGLD 1985. Gage height is not water depth or automatically an elevation above sea level.
    How full is Portage Lake?+
    LakeRadar cannot determine how full Portage Lake is because a verified full-pool benchmark is not cataloged.
    What is the full pool elevation for Portage Lake?+
    A full-pool benchmark is not available from a verified source for Portage Lake.
    What is the water temperature of Portage Lake?+
    The linked sensor's latest stored water-temperature reading for Portage Lake is 56.1°F.
    How is Portage Lake's water level measured?+
    The linked gage-height observations for Portage Lake come from Ludington, MI (automated hydrological monitoring network). LakeRadar stores normalized telemetry from verified in-situ hydrographic sensors.

    Real-time hydrological water levels, surface temperatures, atmospheric forecasts, and marine safety conditions. Return to Portage Lake Dashboard → · Boating Outlook → · Sailing Guide → · Weather & Forecast → · Fishing Forecast → · Radar & Map →