Can I run with an Apple Watch in the rain? I'm starting to feel that none of the Apple Watch designers actually broke a sweat while working out with the watch, nor did they try to exercise in the rain.

I started the Workout app on Outdoor Run, then at about a mile into my run I pulled back my rain-soaked sleeve to find that my workout was stopped about half a mile back, I assume because the water was mistaken for touch input.

With my Garmin Forerunner I could lock the touch bezel but continue to use the side buttons to start, stop, and reset the timer.

Am I missing a similar feature on the Apple Watch?
There's no way to turn the touch input off temporarily, but you can prevent the Apple Watch from stopping workouts early. When you start a workout just go to the watch face the way you normally would, the Workout will run in the background and can't be stopped until you go back to the app and it stop it yourself. It's not perfect, as you can't see your live progress, but it still works.