Great Lakes Ice Cover

Collage of Great Lakes Ice related images. Top row, left to right: An ice breaking ship, a scientist getting a sample beneath the ice, a satellite image of a wintry Great Lakes Region; Bottom row, left to right: an ice covered Lake Erie from satellite imagery, Ice Caves at Glen Haven Beach, an ice breaking ship, and pancake ice.

Understanding the major effect of ice on the Great Lakes is crucial because it impacts a range of societal benefits provided by the lakes, from hydropower generation to commercial shipping to the fishing industry. The amount of ice cover varies from year to year, as well as how long it remains on the lakes. GLERL scientists are observing long-term changes in ice cover as a result of global warming. Studying, monitoring, and predicting ice coverage on the Great Lakes plays an important role in determining climate patterns, lake water levels, water movement patterns, water temperature structure, and spring plankton blooms.

NOAA-GLERL has been exploring the relationships between ice cover, lake thermal structure, and regional climate for over 30 years through development, maintenance, and analysis of historical model simulations and observations of ice cover, surface water temperature, and other variables. Weekly ice cover imaging products produced by the Canadian Ice Service started in 1973. Beginning in 1989, the U.S. National Ice Center produced Great Lakes ice cover charts that combined both Canadian and U.S. agency satellite imagery. These products are downloaded at GLERL by our Coastwatch program, a nationwide NOAA program within which the GLERL functions as the Great Lakes regional node. In this capacity, GLERL obtains, produces, and delivers environmental data and products for near real-time observation of the Great Lakes to support environmental science, decision making, and supporting research. This is achieved by providing access to near real-time and retrospective satellite observations and in-situ Great Lakes data.

Current Ice Cover Conditions

Coastwatch and GLSEA

CoastWatch is a nationwide National Oceanic and Atmospheric Administration (NOAA) program within which the Great Lakes Environmental Research Laboratory (GLERL) functions as the Great Lakes regional node. In this capacity, GLERL obtains, produces, and delivers environmental data and products for near real-time observation of the Great Lakes to support environmental science, decision making, and supporting research. This is achieved by providing access to near real-time and retrospective satellite observations and in-situ Great Lakes data.

GLSEA (The Great Lakes Surface Environmental Analysis) is a digital map of the Great Lakes surface water temperature and ice cover which is produced daily at GLERL.The lake surface temperatures are derived from NOAA polar-orbiting satellite imagery. The addition of ice cover information was implemented in early 1999, using data provided by the National Ice Center (NIC). Lake surface temperatures are updated daily with information from the cloud-free portions of the previous day's satellite imagery. If no imagery is available, a smoothing algorithm is applied to the previous day's map.

Graphs of Percent Ice Cover By Month for the Current Season:


See also:

Click for a Great Lakes basin-wide map summary of current conditions Click for the latest Great Lakes basin-wide ice thickness map from the National Ice Center

Historical Ice Cover

NOAA/GLERL has been monitoring and documenting Great Lakes ice cover since the early 1970's using the ice products developed by the U.S. National Ice Center and the Canadian Ice Service. Research conducted on hydrometeorological processes and regional climate trends has led to models of lake thermal structure that play an integral role in ecosystem forecasting.

Annual Maximum Ice Cover Plots

Click image to enlarge:

Time-series plot of basin-wide historical seasonal maximum ice cover from 1973 to present
Time-series plot of historical seasonal maximum ice cover from 1973 to present for Lake Superior
Time-series plot of historical seasonal maximum ice cover from 1973 to present for Lake Michigan
Time-series plot of historical seasonal maximum ice cover from 1973 to present for Lake Huron
Time-series plot of historical seasonal maximum ice cover from 1973 to present for Lake Erie
Time-series plot of historical seasonal maximum ice cover from 1973 to present for Lake Ontario

Data files:

Great Lakes Ice Cover Database

This database simplifies access to Great Lakes ice cover data by bringing the basic units of data together for the entire time period, 1973-present. The Great Lakes Ice Atlas summarized ice cover for the period 1973-2002, with addendums in a separate report for 2003-2005, in addition to providing a number of statistical products. Using the same methods, the original ice charts for 2006 through present were processed and added to this database.

About the raw data:
Original ice charts are provided in three forms: asci grid files, jpeg image files, and ArcGIS shapefiles. From 1973 through 1988, the source was the Canadian Ice Service. Beginning with 1989, the source was the U.S. National Ice Center, (NIC). Data from both Canadian and U.S. sources is combined in NIC's daily products. Details on file formats, naming conventions are here: asci grid metadata. Files that align ascii grid data with location and lake are here: geographic metadata.

Data files by decade

Original data files by decade. Number of observations per season varies, but for many years was twice per week.

1973 - 1979 1980 - 1989 1990 - 1999 2000 - 2009 2010 - 2017
All grid files (1.2 MB)
All shapefiles (29.5 MB)
All jpg files (6.6 MB)
All grid files (1.9 MB)
All shapefiles (57.8 MB)
All jpg files (12.1 MB)
All grid files (10.2 MB)
All shapefiles (158 MB)
All jpg files (33 MB)
All grid files (14.9 MB)
All shapefiles (699 MB)
All jpg files (63.5 MB)
All grid files (25.4 MB)
All shapefiles (2.1 GB)
All jpg files (210 MB)

Data files by year

Max ice cover image shown for each year. (Click on thumbnail for larger view.) Year summary link leads to ice cover images for entire season.

1973
Max ice cover:
2/27/1973 GLERL digital ice chart for Feb 27 1973
1973 summary
1974
Max ice cover:
2/21/1974 GLERL digital ice chart for Feb 21 1974
1974 summary
1975
Max ice cover:
2/13/1975 GLERL digital ice chart for Feb 13 1975
1975 summary
1976
Max ice cover:
2/3/1976 GLERL digital ice chart for Feb 3 1976
1976 summary
1977
Max ice cover:
2/9/1977 GLERL digital ice chart for Feb 9 1977
1977 summary
1978
Max ice cover:
3/1/1978 GLERL digital ice chart for Mar 1 1978
1978 summary
1979
Max ice cover:
2/19/1979 GLERL digital ice chart for Feb 19 1979
1979 summary
1980
Max ice cover:
3/5/1980 GLERL digital ice chart for Mar 5 1980
1980 summary
1981
Max ice cover:
2/11/1981 GLERL digital ice chart for Feb 11 1981
1981 summary
1982
Max ice cover:
3/9/1982 GLERL digital ice chart for Mar 9 1982
1982 summary
1983
Max ice cover:
2/14/1983 GLERL digital ice chart for Feb 14 1983
1983 summary
1984
Max ice cover:
3/15/1984 GLERL digital ice chart for Mar 15 1984
1984 summary
1985
Max ice cover:
2/23/1985 GLERL digital ice chart for Feb 23 1985
1985 summary
1986
Max ice cover:
2/22/1986 GLERL digital ice chart for Feb 22 1986
1986 summary
1987
Max ice cover:
2/14/1987 GLERL digital ice chart for Feb 14 1987
1987 summary
1988
Max ice cover:
2/21/1988 GLERL digital ice chart for Feb 21 1988
1988 summary
1989
Max ice cover:
3/8/1989 GLERL digital ice chart for Mar 8 1989
1989 summary
1990
Max ice cover:
3/7/1990 GLERL digital ice chart for Mar 7 1990
1990 summary
1991
Max ice cover:
2/27/1991 GLERL digital ice chart for Feb 27 1991
1991 summary
1992
Max ice cover:
2/23/1992 GLERL digital ice chart for Feb 23 1992
1992 summary
1993
Max ice cover:
3/1/1993
GLERL digital ice chart for Mar 1 1993
1993 summary
1994
Max ice cover:
2/14/1994
GLERL digital ice chart for Feb 14 1994
1994 summary
1995
Max ice cover:
3/10/1995
GLERL digital ice chart for Mar 10 1995
1995 summary
1996
Max ice cover:
3/8/1996
GLERL digital ice chart for Mar 8 1996
1996 summary
1997
Max ice cover:
2/18/1997
GLERL digital ice chart for Feb 18 1997
1997 summary
1998
Max ice cover:
2/6/1998 GLERL digital ice chart for Feb 6 1998
1998 summary
1999
Max ice cover:
1/15/1999 GLERL digital ice chart for Jan 15 1999
1999 summary
2000
Max ice cover:
2/18/2000 GLERL digital ice chart for Feb 18 2000
2000 summary
2001
Max ice cover:
3/8/2001 GLERL digital ice chart for Mar 8 2001
2001 summary
2002
Max ice cover:
3/7/2002 GLERL digital ice chart for Mar 7 2002
2002 summary
2003
Max ice cover:
3/3/2003 GLERL digital ice chart for Mar 3 2003
2003 summary
2004
Max ice cover:
2/19/2004 GLERL digital ice chart for Feb 19 2004
2004 summary
2005
Max ice cover:
3/17/2005 GLERL digital ice chart for Mar 17 2005
2005 summary
2006
Max ice cover:
3/2/2006 GLERL digital ice chart for Mar2 2006
2006 summary
2007
Max ice cover:
3/8/2007 GLERL digital ice chart for Mar8 2007
2007 summary
2008
Max ice cover:
3/10/2008 GLERL digital ice chart for Mar 10 2008
2008 summary
2009
Max ice cover:
3/2/2009 GLERL digital ice chart for Mar 2 2009
2009 summary
2010
Max ice cover:
2/8/2010 GLERL digital ice chart for Feb 8 2010
2010 summary
2011
Max ice cover:
2/12/2011 GLERL digital ice chart for Feb 12 2011
2011 summary
2012
Max ice cover:
1/22/2012 GLERL digital ice chart for Jan 22 2012
2012 summary
2013
Max ice cover:
2/18/2013 GLERL digital ice chart for Feb 18 2013
2013 summary
2014
Max ice cover:
3/6/2014 GLERL digital ice chart for Mar 6 2014
2014 summary
2015
Max ice cover:
2/28/2015 GLERL digital ice chart for Feb 28 2015
2015 summary
2016
Max ice cover:
2/14/2016 GLERL digital ice chart for Feb 14 2016
2016 summary
2017
Max ice cover:
3/14/2017 GLERL digital ice chart for Mar 14 2017
2017 summary
2018
Max ice cover:
2/11/2018 GLERL digital ice chart for Feb 11 2018

Daily averages by lake

Daily average ice cover percentages for each lake for period of record, based on simple linear interpolation between original grids. (csv files; metadata)

Basinwide
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Lake Ontario

Links to daily interpolated grid files

References

Additional historical ice data sets and resources

Ice Cover Forecasting

GLERL conducts research on ice cover forecasting on two different time scales: short-term (1-5 days) and seasonal. GLERL's short-term ice forecasting is part of the Great Lakes Coastal Forecasting System, an experimental model used by the National Weather Service to predict wind, waves, currents, and more. The ice nowcast and forecast products (concentration, thickness, velocity, and vessel icing) are still experimental. GLERL's seasonal ice cover forecast is based on statistical and physical analysis. This forecast is also experimental.

Short-term Ice Forecasting (1 to 5 days)

The Great Lakes Coastal Forecasting System (GLCFS) is a short-term physical modeling framework for predicting waves, currents, water temperature, and ice. GLCFS water temperature, air temperature, wind, and the National Ice Center daily ice cover are used to predict ice concentration (%) up to 5 days in the future. Ice forecast products under development include ice thickness, vessel icing, and ice velocity.

The following links to the Great Lakes Coastal Forecasting System pages which contain visual summaries of current Great Lakes ice conditions.

These links to the GLCFS Nowcast/Forecast pages include current observed ice cover, wind, and air temperature as well as model-derived ice thickness, ice velocity, vessel icing, surface currents, and water temperature. Forecast and animations for all parameters are available for up to 5 days. Note that some of these products are still under development.

Superior
Michigan
Huron
Erie
Ontario
Click for the short-term ice forecast for Lake Superior from the Great Lakes Coastal Forecasting System
Click for the short-term ice forecast for Lake Michigan from the Great Lakes Coastal Forecasting System
Click for the short-term ice forecast for Lake Huron from the Great Lakes Coastal Forecasting System
Click for the short-term ice forecast for Lake Erie from the Great Lakes Coastal Forecasting System
Click for the short-term ice forecast for Lake Ontario from the Great Lakes Coastal Forecasting System

Seasonal Ice Cover Forecasting

Research at GLERL has shown that the interannual variability of Great Lakes ice cover is heavily influenced by four large-scale climate drivers: ENSO (El Nino and Southern Oscillation) NAO (North Atlantic Oscillation) or AO (Arctic Oscillation), PDO (Pacific Decadal Oscillation) and AMO (Atlantic Multidecadal Oscillation). Based on statistical and physical analysis, regression models are developed linking climate indices (ENSO,NAO, PDO, and AMO) and annual maximum ice coverage for each of the Great Lakes as well as for the basin. Using these projected indices, a seasonal forecast for Great Lakes ice cover can be made. This is an area of active research at GLERL.


2018 Seasonal Ice Cover Projection for the Great Lakes

GLERL's ice climatologist, in collaboration with the Cooperative Institute for Great Lakes Research (CIGLR), produces an annual projection for Great Lakes ice cover using a statistical regression model based on global teleconnection indices to predict maximum seasonal ice cover percentages for the Great Lakes.

On 1/3/2018, NOAA's Great Lakes Environmental Research Laboratory updated the maximum 2018 Great Lakes ice cover projection to 60%. The long-term average is 55%. The updated forecast reflects changes in teleconnection patterns since early December 2017—movement from a strong to a weak La Nina, a negative to a positive Pacific Decadal Oscillation, and a positive to a negative North Atlantic Oscillation. These patterns combine to create colder than average conditions for the Great Lakes.

Ice cover maxima for individual lakes for 2018 are projected to be:

  • Superior: 68%
  • Michigan: 43%
  • Huron: 62%
  • Erie: 90%
  • Ontario: 29%
  • Great Lakes Ice Cover - Frequently Asked Questions

    What is the current state of ice cover for the Great Lakes Basin?

    Click here to view a map displaying the current extent of ice cover as observed by NOAA Coastwatch's Great Lakes Surface Environmental Analysis (GLSEA)

    How do this year's water temperatures compare with previous years?

    Click the links below to view this and last year's time series of surface water temperatures compared with the long term average (1992-present; via NOAA CoastWatch's GLSEA):

    Superior Michigan Huron Erie Ontario

    When was ice cover the highest (or lowest) for each of the Great Lakes?

    View the records* for Great Lakes Annual Ice Cover (percent) from 1973-2018 below:

    Highest Annual Maximum Ice Cover (%)
    Year
    Lowest Annual Maximum Ice Cover (%)
    Year
    Basin 94.7 1979 11.9 2002
    Superior 100 1996 8.5 2012
    Michigan 93.1 2014 12.4 2002
    Huron 98.2 1994 22.8 2012
    Erie 100 1978, 1979, 1996 5.4 1998
    Ontario 86.2 1979 1.9 2012

    *See Table 1 from: Wang, J., J. Kessler, F. Hang, H. Hu, A.H. Clites, and P. Chu. Analysis of Great Lakes ice cover climatology: Winters 2012-2017. NOAA Technical Memorandum GLERL-171. NOAA Great Lakes Environmental Research Laboratory, Ann Arbor, MI, 24 pp. (2017). http://www.glerl.noaa.gov/pubs/tech_reports/glerl-171/tm-171.pdf

    What does the long-term average look like for maximum ice cover?

    Great Lakes ice cover experiences a LOT of year-to-year variability. This image below illustrates the long-term mean in annual maximum ice cover for 1973-2017.

    from: Wang, J, J. Kessler, F. Hang, H. Hu, A.H. Clites, and P. Chu. Great Lakes Ice Climatology Update of Winters 2012-2017: Seasonal Cycle, Interannual Variability, Decadal Variability, and Trend for the Period 1973-2017 http://www.glerl.noaa.gov/pubs/tech_reports/glerl-170/tm-170.pdf

    Why does Lake Ontario generally have the least ice cover of all the Great Lakes?

    Lake Ontario's extreme depth (86 m average; 244 m maximum) translates to tremendous heat storage capacity. It also has a smaller surface area for heat loss. In addition, cold air outbreaks from the northwest and west are moderated by the waters of Lakes Superior, Michigan, and Huron. These factors combine to keep ice cover on Lake Ontario at a relatively low level most years.

    When does ice cover peak on the Great Lakes?

    Maximum ice cover on the lower lakes (like Lake Erie) normally occurs between mid-February and end of February. Maximum ice cover on the upper lakes (like Lake Superior) normally occurs between end of February and early March.

    Does more ice cover reduce evaporation and lead to higher water levels?

    The relationship between ice cover, evaporation, and water levels is complex. Data on modeled evaporation shows that this process peaks in the fall, before ice cover formation. In a severe ice cover year such as 2014, the thermal structure of the lake could be impacted for the rest of the year, potentially reducing evaporation from the lakes next fall. Evaporation and precipitation are the major drivers of seasonal water level changes in the Great Lakes.

    Does more ice now mean cooler water temperatures this summer?

    Ice extent plays a part in determining water temperature in the lakes later in the year, as incoming heat will have to melt the ice before it warms the water below. However, meteorological conditions and heat storage in the lakes are also critical components to the thermal cycle in the lakes.

    How does blue ice form?

    Sometimes blue ice develops on the Great Lakes. This happens when ice forms that is very compressed with no bubbles. Because of its density and lack of air bubbles, short wavelength light penetrates and scatters in the water below and reflects back through the ice, making the ice look blue. In deep, mid-lake water, where chlorophyll content is low, the reflection of the water can make the ice appear even more blue. This is an unusual phenomenon in the Great Lakes that is usually short-lived.


    Additional Resources:
    Great Lakes Ice Images
    Great Lakes Ice Brochure
    National Ice Center data
    National Snow and Ice Data Center
    Environment and Climate Change Canada Daily Great Lakes Ice Charts

    Contact:
    Media Inquiries
    Margaret Lansing

    734-741-2210
    Ice-Climate Modeling/Forecasting
    Jia Wang

    734-741-2281
    Short-term Forecast Web/Data
    Gregory Lang

    734-741-2250
    Ice cover Web/Data
    James Kessler
    CIGLR

    734-741-2338
    Short-term forecasting
    Anderson, Eric J

    734-741-2293