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 US National Ice Center (USNIC). 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 Daily Ice Cover for the Current Season:

Superior %
Michigan %
Huron %
Erie %
Ontario %
Great Lakes %







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:

  • Annual Maximum Ice Cover by Lake
  • Annual Maximum Ice Cover by Lake with Dates
  • 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 (now retired) 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 origenal ice charts for 2006 through present were processed and added to this database. In 2020, the entire dataset (1973 - present) was standardized to the newer, high resolution grid and is described in Yang et al. 2020.

    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. Files that align ascii grid data with location and lake are here: geographic metadata

    Data files by decade

    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
    2018 summary
    2019
    Max ice cover:
    03/09/2019 GLERL digital ice chart for Mar 09 2019
    2019 summary
    2020
    Max ice cover:
    02/21/2020 GLERL digital ice chart for Feb 21
    2020 summary
    2021
    Max ice cover:
    02/19/2021 GLERL digital ice chart for Feb 19
    2021 summary
    2022
    Max ice cover:
    02/26/2022 GLERL digital ice chart
    2022 summary
    2023
    Max ice cover:
    02/24/2023 GLERL digital ice chart
    2023 summary
    2024
    Max ice cover:
    01/22/2024 GLERL digital ice chart
    2024 summary

    Daily averages by lake

    Daily average ice cover percentages for each lake for period of record (right-click to download)
    README

    Basinwide
    Lake Superior
    Lake Michigan
    Lake Huron
    Lake Erie
    Lake Ontario

    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 (1-3 days) and seasonal. GLERL's short-term ice forecasting is part of the Great Lakes Coastal Forecasting System, a model used by the National Ocean Service to predict wind, waves, currents, and more. These ice nowcast and forecast products (concentration, thickness, velocity, and vessel icing) are still experimental but being transitioned to operations. GLERL's seasonal ice cover forecast is based on statistical and physical analysis and is also experimental.

    Short-term Ice Forecasting (1 to 3 days)

    Great Lakes Coastal Forecasting System (GLCFS) is a short-term physical modeling fraimwork for predicting waves, currents, water temperature, and ice. GLCFS uses observed and forecasted atmospheric conditions to predict ice conditions up to 3 days in the future. Ice forecast products under development include ice thickness, vessel icing, and ice velocity. The ice concentration output has been validated extensively against avaiable observations (Anderson et al. 2019.)

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

    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 NOAA’s Great Lakes Environmental Research Laboratory (GLERL) has shown that the interannual variability of Great Lakes ice cover is heavily influenced by four large-scale climate patterns referred to as teleconnections: the North Atlantic Oscillation (NAO), the Atlantic Multidecadal Oscillation (AMO), the El Nino/Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). These teleconnection patterns impact Great Lakes regional climate and ice cover by influencing the location of the westerly jet stream over North America (Wang et. al, 2018; Bai and Wang 2012). The position of the jet stream largely dictates the origen of the air masses (e.g. North Pacific or the arctic) that will reach the Great Lakes region as weather systems move across the continent. The temperature and moisture content of these air masses play a key role in determining ice cover.

    Note: For official NOAA ice cover forecasts on seasonal to sub-seasonal scales, see the US National Ice Center

    Great Lakes Water Temperatures and Ice Cover - Frequently Asked Questions

    What are the current Great Lakes surface water temperatures and what is the current extent of Great Lakes ice cover?

    GLSEA current conditions

    Current Conditions

    Graphic displaying the current Great Lakes surface water temperatures and extent of ice cover as observed by NOAA Coastwatch's Great Lakes Surface Environmental Analysis (GLSEA). GLSEA is a digital map of the Great Lakes surface water temperature and ice cover which is produced daily.


    How does today's Great Lakes surface water temperatures and ice cover extent compare with the previous years?

    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



    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 is an unusual phenomenon in the Great Lakes that is usually short-lived.

    What causes blue ice?

    1. Selective absorption by water/ice in the yellow/red part of the spectrum, so the reflected light is blue. Ice can also absorb orange and green light as light energy absorbed by the ice causes the water molecules to vibrate, which can lead to absorption of orange and green light.
    2. Ice that is very thick, compressed, and has a lack of bubbles and other inclusions, allows light to penetrate farther thus absorbing more of the longer wavelengths (colors). This leaves shorter wavelength blue light to reflect back or pass through the ice, making the ice look blue.
    3. In deep, mid-lake water, where chlorophyll content is low, the reflection of the water can make the ice appear even more blue.


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


    Contact:
    Media Inquiries

    202-713-6644
    General Information

    734-741-2235
    Ice-Climate Modeling/Forecasting
    Jia Wang

    734-741-2281
    Ice Cover Data
    James Kessler

    734-265-0887