DWR stands for Durable Water Repellent—it's a treatment applied to the fabric that causes water to bead up and roll off rather than soak in. It won't keep you dry in a downpour, but it handles light rain, road spray, and damp trails surprisingly well.
The real benefit of DWR-coated pants is the balance they strike. You get meaningful splash protection without the clammy, sweaty feeling that comes with fully waterproof rain pants. They still breathe well, so moisture from your hard efforts can escape. That makes them especially popular for mountain biking and commuting, where conditions can shift mid-ride.
Just know that DWR coatings aren't permanent—they wear off over time with washing and use. The good news is you can reapply the treatment with spray-on or wash-in products to restore the beading effect. If you regularly ride in variable weather or want some insurance against wet roads without overheating, DWR-coated pants are a smart choice.