I decided to hike Mt St Helena despite the rainy weather. I bought a giant poncho this winter so that I wouldn't have to cancel a hike just because of rain. The poncho worked great – it's so big it covers my backpack and goes all the way down to my knees (at least in the front). It kept me warm and dry despite the wind and rain. Sadly there were no views at all from any part of the hike due to the weather, but I've does this hike before so at least I knew what the views should have been. If you haven't done this hike yet and want to wait a bit, I'd recommend going in the fall, Oct/Nov, as the weather is no so hot and you get beautiful views of the vineyards in full fall colors.