From this image, taken from the rear of one of the railcars used on our various trips over the Donner Summit, you would think that snow is a constant.
And you would be wrong. More often than not, you see it on the ground, not in the air.
Not that there is anything wrong with snow in the air. We had one trip, years ago, where a couple rode the rear platform in polar suits. Really enjoyed the cold weather. Another trip fondly recalled, found us making a moonlight crossing, with the train over 10 hours late, but plenty of folks outdoors taking it all in. I myself recall one especially relaxing moment stepping out into light powder. Just the thing to cool off after toiling in a very hot kitchen!
The best of both worlds? Safe and warm inside, with a smart cocktail in hand rolling the miles by. That’s how I fight off the snow.