Climate in the Mt. Etna grape-growing region

In a recent Mt. Etna wine masterclass held in London, Ian D'Agata pronounced that a combination of three factors contribute to the "special" nature of the region's wines: (i) an alpine climate in a Mediterranean land; (ii) volcanic soils: and (iii) the predominance of ungrafted, pre-phylloxera vines (http://www.decanter.com/wine-news/opinion/the-editors-blog/etna-wines-volcanic-soil-306217/). In this post I will explore the first of the mentioned factors.

At 3,350 m (10, 991 feet), Mt. Etna is the highest mountain in Sicily. Marco Perciabobco of the Department of Agriculture, Sicily Region, describes the region's climate as "mesotermic humid sub-tropical with dry summers." He sees it as a typical Mediterranean climate characterized by an average temperature (coldest month < 18℃, in warmest month > 22℃) and a rainy period mostly concentrated in the autumn and winter months. Rainfall in the region is distributed as follows: between 1.000 and 1.200 mm/yr on the northern, eastern, and southeastern slopes and 500 mm/yr on the southwest slopes.

According to Nesto and di Savino (The World of Sicilian Wine), at the highest elevations for viticulture, the climate is similar to North Italy's, becoming more Sicilian as you proceed downslope. As a result, growing environments differ depending on altitude and aspect.

Etna elevation map. Source: mmsolucoesweb.com.br

The chart below shows the impact of altitude on the grape-growing environment. According to Nesto and di Savino, conditions at the highest elevations are particularly helpful for white and rosato wines and grapes used in their production can be found growing as high as 1300 m (4265 feet). These high-elevation climatic conditions also reduce the incidence of vine pests and diseases and naturally limits vine yield. Below 900 m, conditions become more suitable for red wine production.

As shown on the below chart, growing conditions are also significantly impacted by aspect.

Data from Nesto and di Savino

The Nebrodi Mountains offer some protection to the north slope of Mt Etna but some wind does make it over the top, bringing rain in the autumn and winter and moisture year-round. There are some benefits to this moisture though. The runoff, unlike the case for the runoff on the eastern and southeastern slopes, proceeds downhill at a moderate pace and is absorbed by the lava beneath the soil, This water store then becomes available to the vine roots during the growing season. The major beneficiary of this process is the area between the towns of Solicchiata and Randazzo. The wind from the northeast blows steam from the vents to the southeast creating a shadow which serves to reduce evaporation.

The southeast and eastern slopes are unprotected from the autumn and winter rains but the combination of rapid runoff and early morning sun contribute to their attractiveness as growing regions (especially for whites).

The west slopes are generally the worst for quality wine production because of the late arriving sun.

I will cover the Mt Etna soils in my next post.

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