Colder weather clothing

here in portland or you don't know what the weather will be like it can be Fine then start raining in the middle of a ride or rain on the ride home from work but not in the morning or anything in-between. so now I carry a extra pannier with my rain gear and soon winter gear. I har=te wearing rain gear so I save it till I have to wear it.
That's what I do. Keep enough rain gear and additional clothing items with me so I can be comfortable regardless of what Momma Nature decides to display. The double-ended bar-bag carries 6 lbs. of rain gear, clothes, and an opaque bike cover. It stays on the bike 95% of the time even when I drop the panniers, trailer, and handlebar-bag.