I tried layering when I traveled somewhere cold, where the high was just above freezing. I felt foolish whenever I went indoors and had to peel off three or four layers in order to feel comfortable.

The next time I went, I brought a proper winter jacket. When I was indoors, I took off my jacket. It was simpler and more comfortable, both outdoors and indoors. You cannot replicate a winter jacket with a rain shell and a bunch of layers.

The Bay Area has a lot of microclimates but none of them are really cold nor hot or humid.