Weather Insider: Factors that impact fall foliage
Fall is a season of change, especially in terms of temperatures and foliage. Unfortunately, the Coachella Valley doesn't get to witness the phenomenon of changing leaves thanks to our hot climate and lack of deciduous trees (trees that lose their leaves in the fall).
There are a number of factors that can affect how and when leaves change colors throughout the season. For instance, the more stress a tree experiences (such as drought and extreme heat), the more likely it is the tree will drop its leaves sooner. Also, warmer nights throughout the season will lead to leaves dropping later on.
There are also some factors that can impact the color of the leaves themselves. For example, cooler nights will allow the leaves to produce brighter colors. Warmer nights produce muted, dull colors.