Due to varying exposure, the cooling influence of the nearby ocean (or conversely, the protection from it) and also the significant changes in altitude as the region merges with the hills, there is substantial mesoclimatic variation throughout McLaren Vale. Summer rainfall is low and irrigation is considered essential. Site selection and the marriage of site to variety are all important; Shiraz, Cabernet Sauvignon, Grenache, Semillon, Sauvignon Blanc and Chardonnay all do very well in the appropriate location. Riesling tends to be subtle and delicate in youth but ages well. Pinot Noir is used mainly for sparkling wines.