I have noticed that many days this past winter, the temperature difference between the daily high and low was significantly less than the normal winter difference of 14 or 15 degrees. Is this common?
This winter provided a perfect storm for small daily temperature ranges. One of the main reasons was an excessive amount of cloudiness that not only helped depress daytime highs, but also limited nighttime radiational cooling preventing overnight temperature drops. Another reason was the lack of persistent and deep snow cover that dramatically lowers overnight temperatures on clear, calm nights. This past meteorological winter produced just six days with minimum temperatures below 10, including the season’s lone subzero, a low of minus two on Valentine’s Day, compared to the city’s long-term average of 20 days.