Warm days and cool nights are good, hail is bad and more on the meteorology behind an awesome or awful vintage.
How Weather Affects Wine
Vintage is about the last thing most casual wine drinkers look for on a label, but it can be a great indicator of what’s going on in the bottle. The best vintages, in any region, have a growing season that’s consistently warm day to day, with cool nights; no frost after budbreak; and rain in the growing season but not during harvest. In years that deviate from this ideal, the effect is noticeable. Hot vintages can result in higher alcohol levels, very ripe fruit and lower acidity; cold-vintage wines tend to be lighter bodied with higher acidity. If it’s too cold, grapes won’t ripen enough to be made into wine at all.
How to Save a Vintage
Wine growers and meteorologists are in competition for the title of “most weather-obsessed.” Since the earliest days of winemaking, producers have been devising more-advanced ways to protect their vines. Today, many wineries use wind machines or even, in rare cases, helicopters to fend off frost. In hail-prone places like Argentina’s Mendoza, growers cover vines with nets or shoot off hail cannons, which create shock waves in clouds to break up ice crystals. In regions that permit irrigation, growers can use infrared sensors to pinpoint which parts of a vineyard most need water in a drought.