Dear mmmdumplings,
My wife and I walked the Camino in September and the weather was generally wonderful. Some times wet, occasionally brisk but nice. And we had the first hurricane to hit Spain in 30 years to boot.
We layered. Tee or undershirt, Exofficio outer long sleve shirt, occasionally a packable waterproof (Goretex) windbreaker, which also doubled as a pillow for me, and a poncho which covered.
We mostly wore shorts, but each of us took one pair of those pants that zip off to become shorts, that came in handy a few days.
An outer and thin inner pair of socks helped on chilly days. We took 4 pair of socks and changed every day at noon. That and comfortable, broken in shoes and we never had any foot problems. Even when wet...
Fleece is nice, but if it's not water proof or resistant, you will need a waterproof cover of some type, one that serves more than one purpose is good.
Last, you can always buy something if you really need it.
My pack weight was 22 pounds and my wife's was 15.
Hope some of this helps.
Buen Camino,
Jerry