Summer in Bordeaux can get so hot that you’d wish you could go visiting the chateaux in T-shirt, a pair of shorts and sports-shoes. Except that that won’t do.
Bordeaux, particularly in the Médoc, observes an air of formality that, even with the harsh heat, still expects a jacket. You may however dispense with the tie. With very good friends, things can of course be more casual.
More precisely, it should be described as maritime and temperate.
This is because Bordeaux is flanked by the waters of the Atlantic Ocean to the west, which helps regulate temperatures. Its climate is also influenced by the Gulf Stream (warm sea current that originates in the Caribbean) and the Landes Forest which shields it from the blustering Atlantic winds.
We must also not forget the tempering effect of the Garonne and Dordogne, nor the Gironde estuary that these two rivers become.
Bordeaux’s relatively mild climate ensures the weather is not usually subject to wild swings but is instead quite stable. The grapes ripen gradually, the drawn out process vital for producing wines of complexity and longevity.
Summer temperatures are warm to hot although for someone from the tropics such as this writer, they are very bearable indeed. But as I observed at the beginning of this article, it can get intensely hot (approaching 40 degrees celsius). Maybe it’s global warming at work here.
Autumn, I find, is an even nicer season since it tends to be warm and cool at the same time, and with the scenic vineyards ‘on fire’ as a result of the changing colours of the leaves.
Winter is cool to cold although anyone coming from Beijing, certainly Heilongjian, wouldn’t think so. The temperature seldom gets to zero. More importantly to winegrowers, there’s little frost in winter (although in February 1956, for several days, temperatures dropped to as low as minus 15° celsius, and killed many vines).
Spring is an important time of the year both for lovers and the winegrowers (who of course may, or may not, also be in love) for this is when the vine buds. Frost in spring will send a shudder down the spine of the winegrower because, if severe (as was the case in April 1991), it can kill the young shoots in the nascent buds and strangle the entire year’s growth. Otherwise, Spring tends to be mild in Bordeaux. Only human hearts get more passionate.
HUMIDITY
Given that the region of Bordeaux is surrounded and traversed by water — the Atlantic Ocean, the Garonne and Dordogne Rivers, and the Gironde estuary — it is only to be expected that the region has a relatively high level of humidity in the air. In fact, it is about 80%. While high relative humidity
at the wrong time can lead to unwanted rot in the fruit (one reason the Muscadelle is being phased out by white winegrowing producers), otherwise, in those areas making sweet wines, morning mist is a welcome sight for the development of noble rot or botrytis cinera.
RAINFALL
All farmers, as winegrowers basically are, are concerned about rainfall.
Whereas most farmers pray for rain, especially during the time when their crops need to grow, Bordeaux winegrowers tend to prefer rain in its absence (since if the roots of the vines are deep enough, water can be found in the ground). Entirely no rainfall for a prolonged period is of course not something that even a winegrower would wish for.
Bordeaux’s average annual rainfall is anywhere between 900 and 1 200 mm. Perhaps more important than the consideration of rainfall itself, is when the rain falls.
December and January are the wettest months, while July and August tend to be the opposite.
Rain in June, when the vine is flowering, can wash away the pollens resulting in coulure, the flowers not forming into fruit. Millerandage, a related, but different, problem is the phenomenon whereby some of the grapes do not grow properly in the same bunch with other healthy grapes.
Rain in summer, if followed by warm weather, may also lead to rot. When this happens, a constant breeze or wind would be much appreciated by the winegrower as they will help dry up the grapes, thereby reducing the risk of rot (the same could be said if rain should fall during harvest time when the danger could be even higher since the skins of the grapes are thinner and the bunches tighter). Rain during the
harvest — usually around the middle of September or early October (except for the sweet wines) — also has the potential of diluting the flavours in the grapes, thereby resulting in watery wine. Many a potentially great vintage has had the carpet pulled from under its feet in this way.
Apart from rain, hail, less common of course, also presents a danger. Hail tends to be very localised and depending on where this occurs, it can cause serious damage to both the grapes and the wood of the vine.
Storms are also watched with concern although in the destructive storm that fell so many thousands of trees like toothpicks throughout France on 27th December 1999, the lowly creeper that is the vine, thankfully, survived Nature’s big blow.
SUNSHINE
This great, natural energy is of course crucial to the grapes accumulating sugars and forming flavours.
Ironically, while the sun helps ripen grapes, if it gets too severely hot - as happened in August of 1989 and 1990 - the grapes 'shut down' and the ripening processing is halted.
Overly ripe vintages, without vital accompanying acidity, can result in flabby wines. Combined with winemaking techniques aimed at making chunky, in-your-face grape juice, the result can be bordeaux that resemble New World fruit bombs, rather than epitomes of finesse that Bordeaux is historically renowned for.
LOCAL, MICRO-CLIMATE
Two places sharing the same climate can actually have different weather as expressed by sunshine hours, levels of humidity, inches of rainfall, strength and persistence of winds, etc.
The city of Taipei provides a good example. Downtown Taipei is perceptibly warmer than cool Yangmei San in the hills, just several minutes to drive from the bustling city.
The same can be said if one were to compare the Malaysian capital of Kuala Lumpur with that of almost temperate Cameron Highlands (they grow strawberries there), just two or three hours by car from the tropical city.
People living in mainland China, those near a desert, will appreciate even more dramatically the differences in weather that two places in the same climatic zone can produce. One place can be very wet while another intensely dry.
While Bordeaux, as a region, experiences a temperate, maritime climate, the weather of a local or micro-climate in the various communes can be different enough to make a difference in the wine.
Indeed, even within the same commune, vineyards on higher ground are less prone to frosts since warm air rises. Again, vineyards nearer the Gironde estuary experience more even and relatively warmer temperatures than those that are more inland, such as Listrac and Moulis.
The one micro climate that has the biggest bearing on the type of Bordeaux wine the commune produces is Sauternes.
There, humidity roused from the river and its tributary clings mercilessly onto bunches of Sémillon and Sauvignon Blanc grapes even as the warmth of the sun pursues the mist. The extremes combine to produce rotten, but nobly rotted, grapes, which go on to produce a brilliant wine. Nowhere else in the whole of Bordeaux does Mother Nature, in the form of climate and weather, bring about a more dramatic phenomenon.
