Leaves change with the seasons, and now is the time to see them before they all fall off on Sunday. According to Explorefall.com, most of northern Nevada will be past their peak next week, with peak foliage usually in October for the Truckee Meadows. It will be mild through Sunday, with a storm coming in late Sunday into Monday. This won't be a huge storm, but snow is likely in the Sierra. Highs will be in the 50's at 8000' through Saturday, before dropping into the 40's on Sunday and 30's on Monday.
Colder climates tends to peak before lower and warmer elevations. The change in color has to do with chlorophyll production and the amount of sunlight the leaves receive during photosynthesis.
Chlorophyll is what makes leaves green. The sun angle is high during the growing season, and lower in autumn, impacting the amount of chlorophyll leaves make.
As chlorophyll production goes down during the fall season, the green color fades and some of the other colors are able to appear. Saturated vegetation tends to have more vibrant colors compared to dry vegetation.
