We were heading to Zion this weekend, flying into Vegas and see the highs for the weekend are 49-60 degrees. Not exactly my ideal climate for biking and hiking. Weather in Death Valley is mid 80s for the same period. Since we have not been to either destination and we've had a cold, rainy spring.....would it make sense to switch our trip to Death Valley and save Zion for a future period? Just afraid I will want to spend the majority of my time in the shuttles or is it dry desert air that won't feel cold?