Cold Arctic air will settle in over the Great Lakes region for the first part of the workweek. This will send daytime temperatures almost ten degrees lower than normal and bring overnight lows around -20°C. The cold snap doesn't last long, as more seasonable daytime highs return by the end of the week.
Monday will be partly cloudy, but daytime temperatures will only climb to -8°C. Only a little wind will make it feel more like the minus teens.
Tuesday will be mostly sunny, but even colder air moves into the region, bringing daytime highs of -10°C. A weak north wind will make it feel more like -20°C.
Wednesday will be mostly sunny, but the day will start with morning lows near -20°C and afternoon temperatures in the minus teens.
Clouds and warmer air will start to move back into the region on Thursday and Friday. Daytime highs should reach -8°C on Thursday and -3°C on Friday.