It's all relative, Christmas week of 1983 Southern Minnesota had bitter cold. Every night down to -30 or so and highs from -5 to -10. My in-laws were visiting from Illinois, rented a car and drove up. They were with us most of that week then took the rental car to the airport and flew to Florida to visit relatives down there. The day they arrived there the temp dropped to the somewhere in the 20's and the next few days highs only in the 30's. They called and said it felt colder down there than when they were up with us at Christmas. It appears that the humidity, dampness in the air, has a lot to do with this. Talked with friends from Minnesota stationed at the great lakes navel base outside Chicago and they said they had never been colder due to the moisture, lake does not freeze up there? That said I can feel for you down there in Mississippi this week.