Figure 1.This is one of the modified Koopen Classification that can be
used when trying to determine the climate of a specific place. The
classification system was made by german botanist Waldimir Koppen.
Pic credit:(http://www.fas.org/irp/imint/docs/rst/Sect14/Sect14_1d.html)

Italy's Climate 

Italy’s borders touch as far south as the Mediterranean and as far north as the Alpine mountain range. Although its climate is dominated by a Mediterranean climate the vastness of the country offers many different climates as we can look up in the Koppen scale. As defined by the Britannica website, “Köppen’s classification is based on a subdivision of terrestrial climates into five major types, which are represented by the capital letters A, B, C, D, and E. Each of these climate types except for B is defined by temperature criteria. These are subdivided, with additional letters again used to designate the various subtypes. Type A climates (the warmest), Type E climates (the coldest) are conventionally separated into tundra The mid-latitude C and D climates are given a second letter, f (no dry season), w (winter dry), or s (summer dry), and a third symbol (a, b, c, or d [the last subclass exists only for D climates]), indicating the warmth of the summer or the coldness of the winter. 

Figure 2. This is an average temperature chart of Palmero
over a 4 year period. It was used to help estimate the Koppen
climate. Pic credit: http://www.knowital.com/weather/sicily/

Palmero, Sicily, for example, coldest month drops right around 17-18 degrees Celsius, putting it in the "C" category in the Koppen scale. It does not rain much or at all during the summer so it could be placed in the "s"  sub category. As far as the warmest time of the year it is above 22 degrees Celsius, so could be considered a "Csa" in the Koppen classification system! (all information gathered was from figure 2).

Soil

With Italy stretching so far north and its elevation changing so much it has the perfect conditions to harbor some of the best soils to make wine!  Italy, produces almost 25 percent of the worlds wine and it is because of the perfect conditions( humidity, elevation, soil content) that are found in the Tuscan region of the country. Tuscany occupies 22,933 sq km of the Italian peninsula, where much fo the landscape are rolling hills. There are 64,000 hectares (160,000 acres) of vineyards nestled among these hills.(verticulture) The areas soil is composed of the perfect combinations of, calcium-carbonate, clay, sandstone, and iron. 

References
Britannic- http://www.britannica.com/EBchecked/topic/322068/Koppen-climate-classification
Verticulture- http://www.discovering-wine.com/scenes.html