The results of this research will provide a valuable framework for cultural management decisions and future research on the physiology of the avocado. A more complete understanding of the tree’s response to environmental stresses will be a direct outcome of this research. The results of this research will validate the high temperature sensitivity of ‘Hass’ and will explain why this variety is not necessarily well adapted in warm inland valleys. The impact of high temperature on carbon assimilation may very well explain the smaller fruit size and lower overall yields experienced in dry and hot inland valleys as compared to coastal environments. This in turn will help define grower best management practices that can be utilized to mitigate stress.