At a Glance

Much colder temperatures have moved into the Midwest for the second half of January.As a result, ice coverage in the Great Lakes grew rapidly in the past week.Ice coverage usually peaks in late winter.

Ice coverage across the Great Lakes has more than doubled in the past week due to a weather pattern change that has sent much colder temperatures into the central and eastern states.

On Jan. 15 the amount of ice coverage for all the Great Lakes was near 10 percent, which is below the average of 16 percent for that date. But by Jan. 22 , across all five Great Lakes was at 23 percent, according to the Canadian Ice Service of Environment Canada. That's slightly above the 30-year average (1981-2010) of about 19 percent for that week.

Highlighted in red on the graph is the weekly percentage of ice coverage in the Great Lakes for the season as of Jan. 22, 2019. The long-term average ice coverage for each week is depicted by the green line.

(Canadian Ice Service - Environment Canada)

Cloud-free satellite images of the ice can be difficult to obtain this time of year, but you can see some of the ice growth in the animation below.

The image from Jan. 4 show that lakes Michigan, Huron and Erie were mostly ice free. Just four percent of the Great Lakes were covered by ice around that time. In the image obtained Jan. 21, several pockets of ice are clearly visible.

Satellite image comparison of Lake Michigan (left), Lake Huron (upper right) and Lake Erie (lower right) from Jan. 4 to 21. The red arrows point to areas of ice that have developed on the three lakes between those dates.

(NASA )

The rapid growth of ice has been fueled by a much colder weather pattern gripping the Midwest to start the second half of January.

Average temperatures in most locations in the Great Lakes region were several degrees below average for the week ending Jan. 22, 2019. The first half of January had temperatures that were well above average in the same locations.

Temperatures are forecast to remain . That will likely cause an additional expansion in ice coverage across all of the Great Lakes through the final days of January.

Departure from average temperature in the week ending Jan. 22 across the Great Lakes. Most locations had temperatures several degrees below average.

(Southeast Regional Climate Center)

Great Lakes ice cover typically begins to peak from late February into the start of March. Weekly ice coverage in that period of time is typically 35 to 40 percent based on the 1981-2010 average, according to Environment Canada's data.

Lake Erie typically sees the most widespread ice cover each year given it's the shallowest of the Great Lakes.

NOAA's Great Lakes Environmental Research Laboratory (GLERL) also tracks ice coverage in the Great Lakes. We are unable to provide GLERL's statistics since due to the partial government shutdown.