Warm days and cool nights are good, hail is bad and more on the meteorology behind an awesome or awful vintage.

By Megan Krigbaum
Updated May 23, 2017
Credit: © Ben Wiseman

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.

Weather Emergencies
Winemakers’ worst nightmares.

1. Late-Season Rains
When grapes are ready to be picked, they’re very plump and form tight bunches. If rain gets into these clusters, mold and mildew can grow easily. Rains late in the season will also dilute the flavors in the wine.

2. Hailstorms
Hail has been ravaging vineyards in large swaths of France and Italy over the past several years. Not only can the stones hurt grapes, but they may also shred the leaves (which protect the fruit) and cause long-term damage to the vines.

3. Heat Spikes
Grapes don’t respond well to any rapid temperature change, but heat spikes are especially problematic because the fruit can overripen quickly—or even turn into raisins.

4. Frost
Grapes are very vulnerable to frost from the time the vines blossom until harvest. Early frosts can stop grapes from growing; late frosts are only a benefit in regions that produce ice wine.

Wines to Try
Bottles from regions with excellent recent vintages.

2013 County Line Chardonnay ($28)
Winemaker Eric Sussman used fruit from California’s ordinarily cool Sonoma Coast to make this outstandingly juicy, vibrant Chardonnay.

2013 Huia Sauvignon Blanc ($18)
New Zealand’s Marlborough has notoriously great weather, and this year was spot-on. The Sauvignons, like this organic one, have real depth of flavor and mesmerizing acidity.

2012 The Eyrie Vineyards Willamette Valley Pinot Noir ($35)
After two cold, rainy years came this near-perfect one. Jason Lett worked with vines his dad planted in the ’60s to produce this concentrated Pinot.