If you like wearing overcoats or just like the way they look on people because of their sophisticated attention to detail when worn with suits. You would be wise to wear one your self. There is simply no reason to go out when the weather isn't exactly nice outside without wearing one for both keeping you warm and protecting your suit. Why would you want to get wet any way.
This charcoal double breasted coat is perfect for wearing over a suit when the weather is cold.
Make sure that you order your exact suit size for best fit. These coats are already cut to assume that you'll be wearing a suit underneath. So if your suit size is 42 reg, then you need to order a size 42 reg coat for a proper fit.