Contrast that scenario with a backcountry run where I’d be out for hours, over varied terrain and elevation. In that case I would instead opt for rain protection—in other words, try to stay at least somewhat dry. That would mean a thin long sleeve synthetic shirt with a thin nylon vest over it. Sure, over time I’d get wet anyway from rain penetration and sweat, but I’d be wearing a layer and a half of insulation that would help keep me warm during those walking breaks or if the wind kicked up. I also always carry a space blanket and some fire-starting materials should I ever be incapacitated on the trail until help would arrive.
Help would arrive for you, wouldn’t it? You DID remember to tell somebody—even if it was a voice mail—to some level of detail where you were gonna be, right?