more years ago than I care to remember I was helping out with a charity rummage sale. As I was sorting through donations for display I came across one of the best finds I've ever had. A brand new pair of
GoreTex mitten "shells". Those of us helping were allowed to purchase items for whatever the woman in charge gave as a price. Most of the other volunteers were elderly women who were more interested in small china dishes and bits of fabric and they said, "Oh just take them." I think I ended up giving them a dollar for them.
What makes these perfect is that they work great in the summer, too. They're very light weight, roll up into a neat little cigar sized package and with a pair of lightweight "runners" gloves (neoprene) or even just my cycling gloves under them they are great for keeping my hands dry.
In the winter they are my final layer. I layer my hands in winter, using the thin neoprene "runners'" glove under either a thick mitten or heavier duty glove and then the gore-tex shell over everything.
Most "waterproof" fabrics have two downfalls, IMO, first if they are pressed against the skin by wind or simply the deluge of water they tend to lose their capacity to repel water. Second, even the best of them will not dissipate sweat if it's really warm out or you're working really hard and so the internal moisture is your own- not from the outside.
I know it's totally verboten but I often use cotton- winter or summer- as my base layer under my rain gear. I start with a soft absorbent cotton layer closest to the skin- basically an old tee shirt. Then a very thin polypropolene tee shirt, then the rain gear. I bring an extra tee shirt to change into at my destination. For some reason this works for me and is most comfortable. I find polypropolene next to the skin somewhat uncomfortable and actually feels like it makes me sweat. The cotton tee shirt, on my relatively short commute, absorbs the sweat and will be relatively damp but not soaking by the time I get to work.
These layers give just enough space for the rain gear to do the trick.