Yes. The saddle isn't the limiter in the "how much rain" question. I'll pretty much ride through anything for one day. If I'm "ahead" of where I want to be I might wait out a day of hard rain here or there - if it is continuous or if I'm on gravel/mud roads. However, that is more me being a wimp than concern for the saddle.

My first brooks eventually cracked, tore and wore out, but that was after quite a bit of touring. My second is still going strong including a number of rainy rides.