Per a tip read on BF, I picked up a couple of merino wool sweaters from the local thrift store. This past weekend it was in the upper 50's and low 60's during the day. My day out was to a e-bike exhibit using bike and train plus a stop at the mall. I wanted to be warm but not overheat while riding and also comfortable when not riding. Since I was going to be around people, I also didn't want to smell. I tried out a light-medium weight wool sweater rather than going with a synthetic jersey plus jacket or civilian cotton shirt with jacket. And I made the right choice! Whether riding or not--outside or walking around in the mall, I was pretty comfortable. Sure, when the wind kicked up, I felt the breeze for a bit but then my body temperature would stabilize to a comfortable level again. The most impressive part was when I returned home, I did the sniff test and I barely noticed anything. There was a faint odor but it wasn't the sweaty jersey odor, but more like the very faint mixture of Dawn and wool (I wash delicates with original Dawn dish soap).

I'm definitely sold on wool for cool or cold weather cycling. For next summer, I'm going to experiment with very lightweight long sleeve cotton shirts/blouses. My arms are way over-tanned and I dislike the mix of sweat and enormous amount of sunblock. Hopefully a very lightweight shirt will mitigate the long sleeves in terms of heat. I'm going with cotton as it stinks a little less than synthetics. And there's no need to worry about getting cold from the moisture as the summers here are hot and humid all day and night. It's not like I'm riding in the CA desert where it's very hot during the day and the temperatures drop 20-30 degrees after sundown.