Quality Wine Starts With A Region's Climate. What Does That Mean?

By Cole Swanson
January 1, 2025

Grape growing follows climatic patterns of a region. A grape varietal may ripen better in one region than another, and so viticulturists and winemakers decide which grapes to plant and where based on climatic factors.

A climate is defined by the average temperature of a grape growing area within a single growing year. Ranging from cool to hot in temperature, different climates are better suited for particular grape varietals.

Not all varietals ripen on the vine equally – some ripen more quickly, while others take longer. Certain varieties cannot grow if the climate is too warm, while others fall short if temperatures are too cold. All of this is because of the structural makeup of the specific grape varietal.

However, in many cases, the location in which a grape is able to be planted is not black and white. Therefore, grapes that may otherwise prefer an overall cooler climate, can grow in warmer areas because of the differntiating temperatures in smaller sub-regions.

If one were to consider the entirety of Australia, for example, they would most certainly be correct in defining the overall climate as warm to hot, and also be understood regarding their confusion as to why Riesling, a grape that grows best in cool climates, does so well on this continent.

It is because within the region of South Australia there is a sub-region named Eden Valley, which has a cool climate.

Sub-regions are parts of the whole that have been divided into smaller growing sites because their climatic and geological influences differ from the entire region. The result is wines that are unique to the whole.

These smaller sites directly impact which grapes are able to be planted and how they will grow. In the case of the Eden Valley, the vineyards in this area are planted on the hills of the Valley at differing altitudes. At higher altitudes, the climate becomes cooler and the Riesling is able to prosper.

Factors like fog, rain, elevation, earthly latitude, wind, ocean currents all affect the temperature of an area and therefore grape growing decisions and the profile of a wine.

For the rest of this article, we’ll cover the general definitions of different climates and which grapes grow best in these sites so we understand the basis of how viticulturists decide where to best plant vines. Then we’ll provide examples of specific sub-regions whose climates differ from the whole, in order to showcase how those pockets of difference affect grape growing and winemaking.

CLIMATES

Climates are defined by temperature – cool, moderate, warm, and hot – as well as type – continental, maritime, and mediterranean.

It is possible for the climate of a region to overlap between its temperature and type, which is why understanding different climates can be helpful for decoding how a wine may taste.

In wine speak, you may say, Chablis, France has a cool continental climate. 

Cool Climates

A cool climate is defined as a region whose average temperature is 16.5°C (61.7°F) or below.

These climates are generally best for growing thin-skinned grapes that don’t ripen as well in warmer climates, such as Pinot Noir. In the case of this grape, when planted in a cool to moderate climate, the grapes will retain naturally fruit-forward flavors, whereas they would lose them in warm sites. Additionally, grapes that have aromatic characteristics like Riesling and Sauvignon Blanc all perform well in cool climates because thier floral nature is preserved at lower temperatures.

In the overall warm-to-hot Argentina lies the Salta Province. It is here, in the cool climate of the Cafayate region specifically, that the aromatic white varietal Torrontés thrives. Cafayate is about 1700m (5,600ft) above sea level. It is because of the elevation that this grape is able to be planted in the overall warm climate. It has intense fruity flavors of lemon, peach and rose petals.    

Examples of Cool Climate Regions: Yarra Valley, Australia; Chablis in Burgundy, France; Mosel, Germany; Loire Valley, France; Austria; Salta Province Argentina

Grapes that Thrive in These Climates: Pinot Noir, Torrontés, Chardonnay, Riesling, Pinot Grigio/Gris, Sauvignon Blanc, Chein Blanc, Gewurztraminer, Cinsaut

Moderate Climates

A moderate climate is defined as a region whose average temperature is 16.5°C to 18.5°C (61.7°F to 65.3°F).

There are occasions when geographical features cool a growing site while simultaneously ensuring it stays warm enough.

Rioja, which lies in the northern central part of Spain, is made up of four provinces, with climates spanning from moderate in the north to warmer in the south. 

Rioja is rather unique because of the surrounding mountain ranges and vineyard elevation. The Sierra de Tolono mountains protect from cold, rainy winds of the north while the Sierra de la Demanda and Sierra de Cameros protect from the warm winds of the south. These ranges help to keep the temperatures of Rioja consistent and grapes healthy.

Additionally, this area is best known for the red grape Tempranillo, and, in Rioja Alta, it is planted at higher altitudes because it ripens early. At higher elevations, this grape will ripen more gradually, which will balance flavors. Both the moderating effects of the mountains and cooling effects of elevation help Tempranillo from Rioja to be world-class.     

Examples of Moderate Climate Regions: Piemonte, Italy; Bordeaux, France; The Northern Rhone, France; Adelaide Hills, Australia; Rias Baixas, Spain; Rioja Alta, Spain

Grapes that Thrive in These Climates: Pinot Noir; Gamay, Albarino, Tempranillo, Viognier, Chenin Blanc

Warm Climates

A warm climate is defined as a region whose average temperature is 18.5°C to 21°C (65.3°F to 69.8°F).

Warm climates are best suited to grapes with thick skins because temperatures help to ripen their tannins, which is responsible for the flavor of red wine and manipulates its color. Warm climates could be influenced by a lack of rain, latitude, elevation, amount of sun, proximity to a water source, and elevation.

In the case of the Columbia Valley AVA of Washington state, it is many of these. When people think of Washington, they think of rain and clouds. But travel three hours east and you’ll see the opposition. It is in this AVA where winemakers produce big and bold Cabernet Sauvignon wines with a lot of tannins and aging potential. Cabernet Sauvignon has very thick skins and needs much heat and sunlight for its tannins to ripen fully, which the Columbia Valley AVA provides thanks to the Cascade Mountains and earthly latitude. 

The Cascades create a rain shadow effect, which is when mountains stop rain from traveling over them. As a result, eastern Washington is considered an arid desert where it receives only six inches of rain annually. There is also little cloud coverage during the growing season, allowing for consistent heat and sunshine. Its latitude also means this area receives sun for longer than other areas of the world, like the Napa Valley.

Examples of Warm Climate Regions: The Columbia Valley, Washington state, Napa Valley, the Southern Rhone Valley, France; Tuscany; Umbria, Italy; Barossa Valley, Australia

Grapes that Thrive in These Climates: Grenache, Syrah/Shiraz, Mourvedre, Cabernet Sauvignon, Tempranillo, Cabernet Franc

Hot Climates

A hot climate is defined as a region whose average temperature is 21°C (69.8°F) or above.

Grapes that take long to ripen, such as Grenache, need a warm or hot climate. These varieties prefer more sun and heat for longer than a moderate or cool climate would allow. Hot growing conditions are great for grapes that take longer to ripen, and also those with thick skins. It should be noted, however, that Grenache opposes that generality, as it has thin skins – hence why wine can be an overwhelming subject to understand.   

Examples of Hot Climate Regions: The Meseta, Spain; Hunter Valley, Australia; Worcester, South Africa  

Grapes that Thrive in These Climates: Grenache, Mourvedre, Syrah/Shiraz

Continental Climates

Keywords - high continentality, large diurnal range, little rain, warm and dry summers, dry autumn

These are climates that have a great temperature difference between the coolest and warmest months of the year, also known as high continentality. They also have a larger temperature difference between daytime and nighttime temperatures, which is considered a large diurnal range. Additionally, areas like these have little rain, especially during the summer and continuing into autumn, which is when harvest begins. 

These climates are great for providing a wine that is balanced by acidity and sugar because during the warmer, sunny and dry days, grapes’ sugars evolve, and during nighttime, when it is drastically colder, ripening slows down and acidity remains. They also ensure late-ripening grapes receive enough heat. Varieties such as Merlot thrive in these conditions.

Examples of Continental Climate Regions: Beaujolais, France; The Columbia Valley, Washington state; Chablis, France; Champagne, France; Northern and Southern Rhone Valleys of France; Pfalz, Germany; Barolo, Italy; Calatyud, Spain

Maritime Climates

Keywords - low continentality, short diurnal range, consistent rain

These climates are cool to moderate in temperature and have a low continentality and short diurnal range. They are also characterized by evenly-spread rainfall throughout the year, which can help to moderate a region's temperature to keep it consistent. 

This is why Bordeaux, France, which is best known for its Cabernet Sauvignon-dominant blends, can grow such a grape. Bordeaux is closer to the equator, and the maritime influence keeps this otherwise very warm climate moderate, allowing for Cabernet Sauvignon to ripen well.

Examples of Maritime Climate Regions: Bordeaux, France; Galicia, Spain; Rioja, Spain; Pais Vasco (Basque Country); Monterey Bay, California; New Zealand

Mediterranean Climates

Keywords - low continentality, warm and dry summers

The warm and dry summers are what separates a Mediterranean climate from a maritime one. The extra sunlight and heat during the growing season allows for thick-skinned grapes to be planted and for their tannins to ripen fully, just like a continental climate would.

Examples of Maritime Climate Regions: Penedes, Spain; Andalucia, Spain; Languedoc, France; Greece; Maipo Valley, Chile