Our group used to go out here in the PNW every Sunday rain or shine. We didn't ride if there were a chance of ice. Now that we're all geezers, we don't have the enthusiasm for it we used to. But if one dresses properly, rain riding is great fun, very enjoyable. My wife and I did a 75 mile ride in a steady 36° heavy downpour the whole way. After that, we decided that 40° and pouring was our lower limit, but we were in our late 60s then, so already getting soft. I have a photo of us heading out in heavy graupel, big smiles. The motivation is that it's great fun if you know how to dress for it. Dressing for it takes a good bit of experience in not doing it right. If you're uncomfortable, you didn't do it right, simple as that.
Rules:
NO WOOL. Wool get soaked and doesn't dry. It's nasty after it gets wet, not to mention heavy, very noticeable on climbs. So everything poly from the skin out except for wool socks, which work well as long as they're kept dry.
MTB boots and dry suit legs seals will keep them dry.
Another mistake people make is using waterproof or "breathable" jackets, which don't allow the evaporation of large quantities of moisture, either from rain or sweat. A wind jacket is the thing, with enough poly insulation under it to keep a hard rider warm and comfortable when soaked to the skin.
Rain water is how one gets rid of body heat in the rain. In the dry, it's the evaporation of sweat, but that doesn't work in the rain, though the need to get rid of heat is still there. This theory should be obvious, though the practice of it only comes from experience.
Correct layering of upper body garments is the trick. Legs are much easier as they have a wide window of comfort. PI AmFib tights are a good model.
Gloves are always an issue. Gloves with liners which turn inside out are a no-no. One has to be able to get them off and then on again, when soaked. Thick ragg wool is a good choice, with leather or some shell over them in a cold rain. Giro 100 Plus are good. Most gloves are crap. I have a drawer full of gloves, like I have a cardboard box full of saddles. Keep searching.
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