Whenever it rains, I set my expectations that BART will experience some type of delay. Similar to increased accidents on the freeways when the roads are wet, it is almost consistently so that BART service slows down a bit whenever there is rain. I'm not complaining, it's fine, I've come to expected it after all these years. But why is that? Is it because the wetness makes the tracks slippery? Or is it a visibility issue and speed decreases for safety? Perhaps passengers are slower getting on and off with the rain? Maybe it's all of the above. As long as the delays are under 10 minutes, I can tolerate them every once in awhile. :)
It's nice to have some rain though after a very dry year. It also saves me from watering my plants for at least a few more days! They were starting to look very hopeless-- perhaps the rain will help.