Ever since December 21st (the winter solstice) daylight across Northern Michigan has gradually been increasing and will continue to do so until mid-June.
While the shortest days of the year are in December in the Northern Hemisphere, the coldest temperatures typically lag the shortest days by a month or so which takes us into the current month of January. We enter from now through the first couple days of February the climatological coldest two-three weeks of the year.
As an example, the average high/low temperature (a 30-year average) at Sault Ste. Marie for today is 23F and a low of 7F. That is the average of years of data (some years warmer and some colder) That high/low combination will remain the same until February 3rd when the average high goes to 24F and a low of 8F. By early March that goes to 30F average high and 13F average low. This will peak in mid/late July as our warmest weather typically arrives.
So, for the warm weather/summer weather folks, once you get through January, the temperatures do start to slowly climb back upward. It looks like Mother Nature is on cue this time however, with bitter cold and snow arriving early next week. Highs Sunday through Wednesday of next week will only be in the single digits and low teens with below zero readings at night in spots!