Climate is a vital factor in this region's success as a wine region. Warm, temperate coastal areas are contrasted by inland areas (particularly those in the rolling hills for which the region is so famous), where increased diurnal temperature variation helps to maintain the grapes' balance of sugars, acidity and aromatics. One variety that particularly thrives on these hillside vineyards is Tuscany’s signature red grape, Sangiovese.
Arguably the most important of all Italian wine grapes, Sangiovese is the mainstay variety in almost all of Tuscany's top reds. Its long history and broad regional distribution means that it has acquired various names. In Montalcino it goes by the name Brunello, whence Brunello di Montalcino. In Montepulciano, it is known as Prugnolo Gentile. Under the name Morellino it is the grape used to make Morellino di Scansano. Sangiovese also features in Chianti, in which it is joined by small amounts of Canaiolo and Colorino, as well as increasing quantities of Cabernet Sauvignon and Merlot.