English: A blast of Arctic air brought exceptionally frigid temperatures to the Great Lakes region in late January 2019. By February 1, the Great Lakes as a whole were 48 percent covered with ice, according to the Great Lakes Surface Environmental Analysis (GLSEA). Lake Erie, the shallowest of the lakes, led the freeze-up with 92.5 % ice cover. Coverage on Lake Superior was 58.2%, Lake Huron at 53%, then Lake Michigan at 46.2%. Lake Ontario carried 35.7% ice cover.

On February 1 the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite acquired a false-color image of northwestern Lake Michigan. In this combination of infrared and visible light cloud appears white, vegetated land is bright green, water appears deep blue, and snow and ice are electric blue.

Snow covers the land of the western shore, Green Bay appears solidly iced over for most of its length, and chunks and swirls of ice collect over the lake waters near the shore. White cloud streets—a pattern formed when dry, frigid air blows over relatively warmer, moist water—blow from the west across an ice-covered Lake Michigan.