The northern Midwest is colder in winter than the southern Midwest due to latitude differences.

Due to latitude, winter temperatures in the Midwest differ greatly from north to south. Due to its higher latitude and distance from the equator, the northern Midwest experiences cooler winter temperatures because it receives less direct sunlight. Furthermore, chilly Arctic air masses that descend from Canada are more likely to reach northern regions, which lowers temperatures even further. The southern Midwest, on the other hand, experiences milder winters due to its proximity to the equator and the advantages of warmer air and more sunlight. Because of this latitude effect, winter temperatures in the Midwest get colder as you move further north.