43.6 degrees Fahrenheit is the official temperature for Lake Erie offshore of Cleveland as of today, November 28. While that's still a good bit above freezing, as winter progresses and the lake temperature continues to drop we're on the lookout for ice formation.
Due to the depth of our water intakes, we never have to worry about the lake water pulled into our water treatment plants freezing. However, when and how quickly ice forms and how much and how long it covers Lake Erie is all information we track to keep tabs on the condition of our source of drinking water.
Our partners at the National Oceanic and Atmospheric Administrations’ Great Lakes Environmental Research Laboratory (NOAA GLERL) closely monitor the conditions of Lake Erie and the other Great Lakes, including ice cover. NOAA GLERL has been studying ice coverage on the Great Lakes for 45 years. Their data is important in determining and predicting long-term climate patterns, short-term weather patterns including lake effect snow, lake water levels, water movement patterns, spring plankton blooms, and to some extent, source water quality.
There is no definitive date for when ice will form or what percentage of Lake Erie will be covered. Fans of data and predictions can spend quite some time analyzing the Annual Maximum Ice Cover by Year and the Daily Average Ice Cover Percentages to try and guess when Lake Erie will have 1%, 50% and maximum ice coverage this winter season.
When you look at the collective data for Lake Erie – the shallowest and most southern Great Lake which is typically the warmest in summer and the coldest in winter – the average has 1% of the lake covered in ice by Dec. 13 and maximum ice coverage topping out at 70.5% around Feb. 15.
The two most recent winters are examples of how varied ice formation on Lake Erie can be. The prolonged cold snap during the 2017-18 winter had nearly 60% of the lake’s surface covered in ice by Jan. 4, 2018, with peak ice coverage of nearly 91% occurring on Jan. 16, 2018. During the 2016-17 winter, ice coverage averaged around only 6.6% for the season and topped out at just 35.5% on Feb. 8, 2017.
You can use the links in the text above and graphs and tables below to hypothesize when our valuable liquid asset will (or won’t) freeze. Here at Cleveland Water, we’ll be keeping tabs on the lake conditions to ensure the best tasting water is delivered to your tap.
- Lake Erie’s Long-Term Average Surface Water Temperature (as compared to 2018): https://coastwatch.glerl.noaa.gov/statistic/gif/avgtemps-e_1992-2017.gif
- Lake Erie’s Average Ice Concentration Graph for the 2017-18 winter: https://coastwatch.glerl.noaa.gov/statistic/ice/gif/e2017_2018_ice.gif
- Lake Erie’s Average Ice Concentration Graph for 2018-19 winter, which will be updated as we shiver our way through the next four months: https://coastwatch.glerl.noaa.gov/statistic/ice/gif/e2018_2019_ice.gif
- NOAA National Weather Service Average Lake Erie Water Temperatures by Day (1981-2010): https://www.weather.gov/cle/avg_lake_erie_water_temps