Topography: Aspect

Slopes which face the sun through much of the day (southerly aspects in the northern hemisphere, and northerly aspects in the southern hemisphere) are the warmest, and those facing away from the sun are the coolest. The influence of aspect is modified by other climate parameters. For example, the degree of daytime warming is increased by more sunshine and by protection from wind. Differences in soil temperature are important not only for nutrition of the vine, but also for growth and fruiting through export of the growth substance cytokinin to the vine tops.