I'm not a jogger, but I know that jogging generates body heat, and, judging from the way I see joggers dressed, even in the dead of winter, plenty of it.
I think this comes down to personal circumstances.
For instance, when I was researching my Canada Goose jacket I read any number of reviews whose writers said they were comfortable at 20º with no more than a T-shirt under the jacket, whereas I'd be in the back of an ambulance in less than 15 minutes under those circumstances.
