Sunday marks the first full day of astronomical winter, when Chicago’s average high temperature hovers near freezing, and the intensity of incoming sunlight is at its low point. Nonetheless, Sunday and Monday are forecast to feature generous sunshine and temperatures more likely to occur around Halloween. Monday’s forecast high of 57 degrees would be our highest reading since October 27th. Mild, dry weather is not confined to the Midwest. Nationwide, only the West coast and parts of the Southeast are expected to receive precipitation through Monday. Cooler air is due to arrive midweek, but the chances for a white Christmas are only a dream since readings through the end of the week will remain well above freezing. Medium range forecasts suggest that weather more typical of late December may arrive next weekend when a system brings cooler air and a likelihood of rain.