Decades ago I had a very experienced Sierra climbing & trekking guide teach me that the worst weather to be caught in was "35 degrees and raining". He would rather be in a blizzard at subzero temps than be caught out in the wet, just above freezing.

I've been carrying a minimalist sil-nylon tarp from O-Ware for the last few years, even on dayhikes (and I still carry the plastic bags & AMK bivy). I had it made in blaze orange to serve as a signaling tool as well and it weighs under 1 pound. Combined with my trekking poles and some cordage it is very versatile, either alone or integrated into a bushcraft-style shelter.