Two years ago, I ran a 5 mile race in 27:30 in the middle of February. It was 18 degrees during the race. I don't race a lot (maybe twice per year on average, and it's usually either trail races or half marathons), so I don't really have any other races to compare this to.
With that said, my question is this: How much did the cold slow me down? My guess is maybe up to a minute, but I really have no idea. I am going to run a 5 mile race in about a month, and I'm just trying to decide on what I should set for a goal time.