File:Low Ice Cover on the Great Lakes (MODIS).jpg

English: So far this winter, the Great Lakes have been unusually ice-free. As of February 14, 2023, ice covered only 6.6 percent of the five freshwater lakes, which is significantly less than the 35-40 percent ice cover that is typical for mid-February, according to data published by the National Oceanic and Atmospheric Administration's (NOAA) Great Lakes Environmental Research Laboratory (GLERL). The ice cover on February 13 was only 7 percent—the lowest ice cover measured on that date of any year since 1973, when satellite-based record keeping began.

When the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired this true-color image of part of the Great Lakes, cold air temperatures had brought the total ice cover up to 8.3 percent. What little ice is present skirts the coastlines of the lakes, and a strip of ice covers Lake Huron’s Saginaw Bay. In Lake Erie, sediment swirls kicked up by storms and waves, mixed with colors of floating phytoplankton, give the water a marble-like look.

Air temperatures are the main factor affecting ice cover on the Great Lakes. According to the U.S. National Ice Center, each of the five lakes experienced warmer than average air temperatures in January 2023. The average temperature across the contiguous U.S. was 35.2 degrees Fahrenheit (5.1 degrees above average) according to NOAA, making January 2023 the sixth-warmest January on record.

Ice extent across the Great Lakes Basin briefly jumped to 21 percent in early February in response to a cold snap. But since then, it has declined through at least mid-February. Maximum ice cover typically occurs between mid-February and early March.