NASA has released images from earlier this week when over 80 percent of the five Great Lakes were covered by ice, according to the Great Lakes Environmental Research Laboratory (GLERL).
Images were taken by NASA's Aqua satellite on Feb. 19, 2014.
Earlier this month, ice covered as much as 88 percent of the lakes, according to NASA's Earth Observatory.
The lakes have not had that much ice since 1994.
Dating back to 1973, the Great Lakes have reached barely over 50% ice cover on average, the space agency added.
Cold temperatures are largely to blame for most of the thick ice, but scientist Nathan Kurtz, of NASA's Goddard Space Flight Center, said to the the Earth Observatory that "secondary factors like clouds, snow and wind also play a role."
Ice cover over Lake Huron, Lake Erie, and Lake Superior is approaching 100 percent, Lake Michigan is 60 percent covered, and Lake Ontario is only 20 percent covered, according to GLERL.
The ice might cause some trouble environmentally to the nearby region.
"The biggest impact we'll see is shutting down the lake-effect snow," Guy Meadows, director of Michigan Technological University's Great Lakes Research Center, said in a statement, according to NASA.
The lake effect occurs when snow gets dropped on a certain region when weather systems from the north and west pick up evaporation lake water.
The ice cover is supposedly reducing evaporation, which could be a good thing, since the Great Lakes went through record low water levels in 2013, according to LiveScience.com.
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