Have you ever wondered why wine is only made in certain regions around the world? Wine has been a part of human civilization for over 8,000 years. Though not all countries around the world are capable of making it. Actually, all wine growing regions have one thing in common—they’re located between the latitudes of 30° and 50° north and south of the equator. That’s because closer to the equator is much too hot for vines to grow, just as it’s too cold for vines closer to the poles. Let’s look at the best climate for grapes and how weather can influence grape growing and winemaking.
Climate and Weather
A region’s overall climate is determined by analyzing the annual temperature, sunlight, and rainfall patterns over several years. Alternatively, weather considers the current conditions and how they vary from the overall climatic average.
This comes into play in regions like Bordeaux where annual rainfall varies significantly from year to year. Such unpredictable weather is the reason why Bordeaux wines are mostly blends. Producers hedge their bets against mother nature by blending numerous varieties to create consistent quality wines every year. In this way, they are not reliant on a single grape’s crops, which heavy spring or autumn showers could potentially destroy.
You’ve likely heard or read about cool, moderate, warm, or hot climates before. They are generally classified by their average temperature throughout the growing season, which is April to October in the Northern Hemisphere and vice versa in the Southern Hemisphere.
- Cool climate: 61.7°F (16.5°C) or below
- Moderate climate: 61.7°F – 65.3°F (16.5°C – 18.5°C)
- Warm climate: 65.3°F – 69.8°F (18.5°C – 21°C)
- Hot climate: 69.8°F or greater (21°C)
So, why do these classifications matter? The average climate indicates which grapes will be able to successfully ripen in any given region.
For example, late-ripening varieties like Riesling or Cabernet Franc flourish in cool climates. They need that longer growing season to fully develop concentrated flavors and fresh acidity. Other varieties like Chardonnay or Cabernet Sauvignon, can successfully grow in a variety of climates. However, their flavor and structural profiles will vary distinctly from a cool to hot climate.
Main Types of Climates
Depending on the variety, the best climate for grapes falls into these three categories.
Continental climates are generally found more inland. They have the greatest temperature difference between hot and cold months. Typically, a region with a continental climate experiences short hot summers, followed by a larger, rapid drop in temperature in the fall.
Let’s consider a cool continental region like Chablis or Champagne. In the spring, these regions run the risk of frost during budbreak, followed by lower average temperatures throughout the growing season. Those lower temperatures can affect flowering, fruit set, and overall ripening. Therefore, grapes which have a later budbreak in the spring and ripen early in the fall are best suited to this climate.
Maritime climates normally have cool to moderate temperatures, plus smaller temperature variations between the hottest and coldest months of the year. Rainfall occurs throughout the year, which helps keep temperatures more moderate. For this reason, grapes can ripen well into autumn. However, rainfall in the spring and summer can be harmful to flowering, fruit set, and grape health.
Previously mentioned Bordeaux is the perfect example of a moderate maritime climate where grapes like thick-skinned Cabernet Sauvignon can successfully ripen without warm or hot temperatures.
Mediterranean climates also have low temperature differences between the hottest and coldest months. Yet summers are warm, sunny, and dry. Think of regions throughout the Mediterranean, as well as new world regions like California, Chile, and South Eastern Australia.
Wines found in Mediterranean climates tend to be fuller bodied with lower acidity, higher alcohol, plus riper tannins and fruit flavors thanks to warmer temperatures.
Additional Weather Considerations
There are a number of other climatic factors to consider when making wine.
Diurnal range, which is the temperature difference between night and day, is a big one. Depending on the variety planted, diurnal range can be very beneficial to producing quality wines. A larger diurnal range means warm temperatures during the day ripen grapes while concentrating flavors and tannins. Then, the temperature drops at night, helping to preserve acidity and aromas in the grapes. Regions with a larger diurnal range tend to produce fresher and more aromatic wines.
Additionally, spring frosts can be detrimental to vines. Regions like Burgundy, a top climate for grapes such as Pinot Noir and Chardonnay, run the risk of killing newly burst buds or young shoots with frosts in the spring. This occurs if cold air below 0°C collects at ground level and freezes any water vapor on the vines or the ground. In frost prone regions, growers will use heaters, wind machines, and sprinklers to combat spring frosts
Rainfall is another big consideration in wine growing regions. For those that don’t receive enough natural rainfall, drip irrigation, sprinklers, or flood irrigation may be implemented.
Finally, sunshine has a huge influence on grapes. Too much sun can result in overripened grapes with high sugars and more intense tannins. Too little sunshine and the grapes won’t ripen fully, plus you run the risk of drought and water stress on the vine. Viticulturists are able to optimize the sunlight for the vines through careful pruning, canopy management, and planning the vineyard aspects properly.
Generalizations on Climate for Grapes to Help You Shop
While there are many factors to consider, we can make certain generalizations regarding the climate for grapes and how it influences wine. Typically, cooler climates produce fresher, elegant wines because the lower temperatures preserve acidity and allow for a longer growing season in which flavors and tannins develop nicely. Alternatively, warm to hot temperatures experience greater sunshine, developing riper tannins and fruit flavors, plus high sugars which translate into higher alcohol wines. Hopefully, this will help you make better wine buying decisions by understanding the wine behind the label.