The climate in Stellenbosch is most certainly one of the most important contributing factors to the growth of noble wine cultivars. The cooler, wet winters and the dry, hot summers in Stellenbosch are characteristic of a Mediterranean climate.
The characteristic thick skin of Cabernet is indicative of a grape that ripens comparatively late in the year compared to other varietals. The warm climate and daylight hours, approximately 14 hours in summer and 10 hours in winter, in Stellenbosch is therefore paramount to the growth process of the Cabernet grapes which would otherwise not be able to reach their optimal ripeness.
The average temperature in Stellenbosch is 16.4 degrees with temperatures reaching the mid-high 20s during the summer months. Although the vines struggle in extremely hot temperatures, the maritime climate with close proximity to the Indian and Atlantic oceans means that cool prevailing South Easterly wind allows the vineyards some relief from the hot weather during the summer months. These winds also inhibit the development of disease in the vineyards.
With an annual rainfall of between 600mm – 800mm, Stellenbosch vineyards receive plenty of rain. The good annual rainfall means that while there might not be sufficient rains during the summer periods, winemakers are able to store excess water for irrigation when necessary.
In essence, the combination of maritime influences such as ocean breezes and coastal fogs, coupled with a warm Mediterranean climate, makes Stellenbosch one of the most ideal places to cultivate Cabernet with a unique and complex character.