(In response to a question on Cohost about waterproof bike pants) Depending on how your bike is set up, a rain cape can obviate or reduce the need for waterproof pants. [Cleverhood](https://cleverhood.com/) makes lightweight ones that are really nice. A rain cape also is much less of a heat trap than a traditional waterproof jacket, which is great if you sweat at all while cycling. If you have a semi-upright posture on your bike, a cape can cover your knees and above pretty well. You can use leg gaiters to keep your shins dry and [shoe covers](https://www.rivbike.com/products/musa-splats-pair) if you don't ride in waterproof boots. This kind of modular approach may sound like more fuss, but in my experience it's a lot more comfortable than riding in fully waterproof pants. That being said, you can get waterproof pants from REI or anywhere like that. Basically what you want is something that's goretex or a different waterproof breathable membrane, and obviously you want it not to be insulated. It doesn't have to cycling specific. These kinds of garments will not stay totally waterproof forever or under all conditions -- and especially in a driving rain, if you have a long ride, almost any garment will eventually wet out. You could also go for wool instead which won't be waterproof but which will be fast-drying and will not give you hypothermia.