Chicago is currently facing a significant shift in its weather patterns, characterized by lake-effect chills resulting from the influence of Lake Michigan. This phenomenon occurs when cold air moves over the lake's relatively warmer waters, causing localized cooling and increased wind speeds, leading to a drop in temperatures that feels colder than the actual air temperature. The Chicago Tribune reports that these brisk conditions are expected to persist throughout the week, particularly affecting areas near the lakefront where the wind intensifies the cold sensation.