Great Lakes Water Level Dashboard

Superior Michigan-Huron St. Clair Erie Ontario
Surface Water Elevation (meters; IGLD85)
Legend and Menu
Water Level Observations
Lakewide Monthly Average
Lakewide Annual Average
Average for Period of Record (1918-present)
Water Level Monthly Forecasts
3 Month Forecasts (AHPS-Experimental)
6 Month Forecasts (AHPS-Experimental)
Multi-Decadal Water Level Forecasts
Angel et al. (2010) A2 - Multi-GCM
Hayhoe et al. (2010) A1fi - AOGCM
Lofgren et al. (2011) Base Case
Lofgren et al. (2011) A2 - CGCM3 - TA
Lofgren et al. (2011) A2 - CGCM3 - EA
Lofgren et al. (2011) A1B - GFDL20 - TA
Lofgren et al. (2011) A1B - GFDL20 - EA
MacKay and Seglenieks (2012) A2 - CGCM3
Paleoclimate Reconstructions
Quinn, Sellinger (2006) Michigan-Huron
Wiles et al. (2009) Erie
Baedke, Thompson (2000) Michigan-Huron
Johnston et al. (2012) Superior
Select Timespan
Start Year
End Year
Select start and end years, then click OK.
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This dashboard was designed for convenience in examining Great Lakes water levels and forecasts at a variety of time scales. Please direct questions or feedback to:

Anne H. Clites, Physical Scientist
NOAA Great Lakes Environmental Research Laboratory
4840 S. State Rd, Ann Arbor, MI 48108
(734) 741-2282

Other contacts:

Dr. Drew Gronewold, GLERL Research Hydrologist
Program Manager

Joeseph Smith
CILER Developer


The Great Lakes Climate Dashboard is sponsored by the Great Lakes Restoration Initiative (GLRI), the Cooperative Institute for Limnology and Ecosystems Research (CILER), and the Great Lakes Environmental Research Laboratory (GLERL), part of the National Oceanic and Atmospheric Administration (NOAA).

For the HTML5 edition of the dashboard, credit goes to the developers of Dan Vanderkam's Dygraphs.

Lastly, thanks to Cathy Darnell at GLERL for consultation on graphics, and for earlier inspiration, a special thanks to Mark Phillips, creator of Multigraph.

DISCLAIMER: This page contains links to non-Federal government web sites. They do not constitute endorsement of any product, service, organization, company, information provider, or content.

How to Use This Tool

The Great Lakes Water Level dashboard was designed to help users view, understand, and compare Great Lakes surface water elevation data and forecasts from a variety of different sources, and across a variety of time scales ranging from monthly average values, to annual and multi-decadal values. For Great Lakes water level data and forecasts at a higher temporal resolution, we direct users to the NOAA National Ocean Service (NOAA-NOS) Great Lakes water level gauging station site, the Canadian Hydrographic Service site, and the NOAA-NOS Great Lakes Operational Forecasting System site.

The following is a list of tips to help navigate the dashboard:

  1. The time period displayed in all data panels can be adjusted using the time span slider below the time axis.
  2. The legend is dynamic, allowing users to explore different categories of surface water elevation information. From within those categories, users can (by clicking on the appropriate check-box) display different combinations of data and forecasts, and can change the colors in which they are displayed.
  3. The chart for each lake can be displayed, or hidden, using the check boxes in the upper-right corner of the screen.
  4. Units for surface water elevation values can be converted between 'feet' and 'meters' by clicking on the button (initially labeled 'To ft & in') in the upper left-hand corner of the screen.
  5. The scale and range of surface water elevation data within each panel (i.e. the vertical axis for each panel) can be adjusted individually for each lake (using the buttons to the left of each chart) or simultaneously for all lakes (using equalizer field in the bottom left corner).
Surface Water Elevation Data Information

The water levels in the Great Lakes are monitored by NOAA - National Ocean Service in the U.S. (Center for Operational Oceanographic Products and Services) and by the Canadian Hydrographic Service in Canada. Water levels shown here are lakewide monthly averages. Data is available for individual water level gauges and at a higher resolution (daily, 6-minute average) by going to the source agency's websites shown above.

1918-present: monthly lakewide average water levels

In 1992, the Coordinating Committee for Great Lakes Basic Hydraulic and Hydrologic Data approved a set of gauges (U.S. and Canadian) for each lake that water resource professionals believe give the most accurate reflection of the lake's overall water level when averaged. These lakewide average levels are used by the Army Corps of Engineers and Environment Canada in their forecast bulletins. The gauge networks are as follows, with the underlined gauges indicating the master gauges (well established gauges used in the development of lake datum):

Lake SuperiorLake Michigan-HuronLake St. ClairLake ErieLake Ontario
Duluth, MNLudington, Mackinaw City, Harbor Beach, MISt. Clair Shores, MIToledo, Cleveland, OHRochester, Oswego, NY
Marquette, Pt Iroquois, MIMilwaukee, WIBelle River, ONPort Stanley, Port Colborne, ONPort Weller, Toronto, Cobourg, Kingston, ON
Michipicoten, Thunder Bay, ONThessalon, Tobermory, ON

Pre-1918 monthly water levels

Before 1918, there were very few water level gauges in the Great Lakes. However, Superior, Michigan, Huron, Erie, and Ontario all have at least one water level gauge that has been in operation since 1860. They include the gauges considered to be the "master gauges" on each lake. Because of isostatic rebound (shifting of the land surface following the retreat of the glaciers), the levels at these gauges may not represent the lake-wide average level if they are far from the lake's outlet. These historical levels can be adjusted to represent the levels at the outlet. You may compare the adjusted levels (1860-1917) to the original measurement on Superior and Erie by viewing the master gauge and the adjusted monthly average time series (diamonds and triangles respectively). The equations used to adjust these early gauge records are:

SuperiorMarquetteTo Pt Iroquois: PI = -.00108382*year+2.153 + Marquette
Michigan-HuronHarbor BeachNone
St. ClairGross Pointe Yacht ClubNone
ErieClevelandTo Buffalo: Buff = -.001008382*year+2.153 + Cleveland

Per Month Records

Per month averages and record highs and lows for each month are available for the lake-wide average water levels (1918-present). These values are coordinated by the U.S. Army Corps of Engineers and Environment Canada. Data are here in meters, and here in feet.

Pre-1860 Observations

QUINN, F.H., and C.E. SELLINGER. Note. Lake Michigan record levels of 1838, a present perspective. Journal of Great Lakes Research 16(1):133-138 (1990).

Additional perspective on Lake Michigan-Huron water levels is provided by this pre-1860 monthly water level data set recorded in Milwaukee, Wisconsin between 1815 and 1859, encompassing a period of high water levels in 1838. These data were adjusted to the outlet at Harbor Beach to account for isostatic rebound and translated from the Lake Survey Datum of 1877 to IGLD 1955. The data set was updated to IGLD 1985 using a Harbor Beach correction of 0.214 meters.

Monthly Level Forecast Information

These water level forecasts were produced by GLERL's Advanced Hydrologic Prediction System (AHPS) model. GLERL's forecast probability bands for both 3-month (dark) and 6-month (light) forecasts can be shown on the dashboard by checking the appropriate menu boxes. The colored bands show the 90% probability intervals for the month's mean water level. If AHPS was always accurate, these bands would contain the observed water level 90% of the time. GLERL recently started archiving AHPS' forecasts in order to assess its performance. A recent study (Gronewold 2011) showed that the 90% probability band captures between 64 and 74% of the observed water levels, based on the years 1997 through 2009.

More about GLERL's seasonal water level forecast model

The NOAA Great Lakes Environmental Research Laboratory produces a new water level forecast for from one to ten months in the future every day. The GLERL forecast is a research tool, not associated with any operational decisions, however, it is relied on by many governmental agencies and others who need water level information for planning. GLERL's Advanced Hydrologic Prediction System combines historical meteorological data with a series of mathematical models and climate forecasts from NOAA's Climate Prediction Center to simulate multiple hydrologic variables (precipitation, runoff, evaporation). The net 'supply' of water to each basin is routed through the lakes and their connecting channels to produce predicted monthly levels. More information about GLERL's water level forecasts and access to the daily update can be found here.

Croley, T., Lee, D., 1993. Evaluation of Great Lakes net basin supply forecasts. J. Am. Water Resources Association 29(2), 267-282

Croley, T., 1992. Long-term heat storage in the Great Lakes. Water Resources Research 28(1), 69-81.

Croley, T., Hartmann, H., 1985. Resolving Thiessen polygons. J. Hydrology 76(3-4),363-378

Other forecasts available

Several different agencies produce seasonal forecasts for Great Lakes water levels. The U.S. Army Corps of Engineers - Detroit District and Environment Canada have operational responsibilities related to the regulatory authorities for Lake Superior and Lake Ontario. The Corps of Engineers and Environment Canada collaborate to arrive at a single coordinated forecast for the lakes based on the lakewide average levels. Their forecast bulletins are published each month and widely distributed to basin residents.

Multi-Decadal Forecast Information

Many studies have been published in the past several decades that use models to assess the impact future climates will have on Great Lakes water levels. Although a thorough understanding of each study will require reading the source material, the dashboard allows us to put these different projections side by side for visual comparison.

The long term water level projections presented here are from four recent studies:

  • Lofgren, Hunter, and Wilbarger (2011) "Effects of using air temperature as a proxy for potential evapotranspiration in climate change scenarios of Great Lakes basin hydrology" Journal of Great Lakes Research Volume 37 (Some details available here)
  • Hayhoe, VanDorn, Croley, Schlegal, Wuebbles (2010) "Regional climate change projections for Chicago and the US Great Lakes" Journal of Great Lakes Research Volume 36 (Some details available here)
  • Angel, Kunkel (2010) "The response of Great Lakes water levels to future climate scenarios with an emphasis on Lake Michigan-Huron", Journal of Great Lakes Research, (36).
  • MacKay, Seglenieks (2012) "On the simulation of Laurentian Great Lakes water levels under projections of global climate change", Climatic Change.

Click the buttons below for more information on the individual studies' data.

Information on Angel and Kunkel Data

This study used global climate model results from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report, AR4. Three emission scenarios (high, intermediate, and low) were chosen and many runs were completed for each scenario; 565 in all. Between 18 and 23 general circulation models was used for each scenario. GLERL's AHPS was used to determine final lake levels. The base period for this study was 1970-1999. Projected lake levels were reported relative to the average lake level from the base period. Only the extreme emissions scenario projections are reported. The range shown is from 25th (bottom) to 75th (top) percentile.

Information on Hayhoe et al. Data

Hayhoe et al. used both high (Special Report on Emissions Scenarios - SRES - A1fi) and low (B1) emissions scenarios to project future climate. Only the high emission scenario was used to plot change in lake levels (Fig 10 in the reference). Since the data was not available in digital form, values were carefully estimated from this graph. GLERL's Large Basin Runoff Model (LBRM, details here) and Advanced Hydrologic Prediction System were used to generate runoff and resulting lake levels. The base period for these projections is 1961-1990. Hayhoe et al developed projections for 3 time periods: 2010-2039, 2040-2069, and 2070-2099.

Information on Lofgren et al. Data

Lofgren et al. developed a new approach for estimating potential evapotranspiration by using an energy budget-based approach instead of the more common method of using air temperature as a proxy for evapotranspiration. Lofgren's base case is 1958-2005. Using two different climate models and two methods (details below) for calculating potential evapotranspiration yielded 5 projections:

  • Base
  • CGCM3 / Delta method
  • CGCM3 / Alternate Energy Adjustment Formulation
  • GFDL20 / Delta method
  • GFDL20 / Alternate Energy Adjustment Formulation

Climate Models Used:

  • Canadian Centre for Climate Modeling and Analysis' Coupled General Circulation Model Version 3 (CGCM3)
  • Geophysical Fluid Dynamics Lab Climate Model Version 2.0 (GFDL20)

Methods used:

  • Delta method (using air temperature as ET proxy)
  • Alternative Energy Adjustment Formulation (energy-budget based approach)

Both methods employ the GLERL Large Basin Runoff Model and were transformed to lake levels using the Coordinated Great Lakes Regulation and Routing Model.

Information on MacKay and Seglenieks Data

This paper proposes a new method for estimating future net basin supplies and lake levels based on a bias-correction method that enables the direct use of general circulation model output to run evaporation and runoff models, preserving the land surface-atmosphere feedback loop. The general circulation model used here is the Canadian Regional Climate Model (GLRCM). The base period for this study is 1962-1990. Projections are made for the period 2021-2050. Results for the upper lakes are given in terms of lake level change relative to the base period.

Paleoclimate Reconstruction Data Information

Although the 150+ years of recorded water level data for the Great Lakes comprise one of the longest high quality hydrometeorological data sets in North America, it may not necessarily be representative of the last several thousand years during which the Great Lakes have been in their present hydraulic state. Records from paleo lake level analysis, using submerged tree stumps, tree ring data, and ancient shorelines to draw conclusions about past lake levels, climate, and glacial isostatic adjustment, can add context to both our understanding of current lake level fluctuations as well as our attempts to project how future climates and vertical ground movement will impact these levels.

These historical data are from the following journal articles:

"A Reconstruction of Lake Michigan - Huron Water Levels Derived from Tree Ring Chronologies for the Period 1600-1961", Frank H. Quinn and Cynthia E. Sellinger, Journal of Great Lakes Research 32:29-39, 2006

"A 265-year Reconstruction of Lake Erie Water Levels Based on North Pacific Tree Rings", Gregory C. Wiles, Anne C. Krawiec, and Rosanne D. D'Arrigo, Geophysical Research Letters, Volume 36, 2009

"A 4,700-year record of lake level and isostasy for Lake Michigan", Steve J. Baedke and Todd A. Thompson, Journal of Great Lakes Research, 26(4):416-426, 2000.

"A Sault-outlet-referenced mid-to-late Holocene paleohydrograph for Lake Superior constructed from strandplains of beach ridges", John W. Johnston, Erin P. Argyilan, Todd A. Thompson, Steve J. Baedke, Kenneth Lepper, Douglas A. Wilcox, and Steven L. Forman, Canadian Journal of Earth Sciences, 49:1-17, 2012

Welcome to the Great Lakes Water Level Dashboard!

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