There is a joke among grape growers that they are never happy because it is either too wet, too dry, too hot or too cold.

But for Prince Edward County winemakers, fluctuations in temperature and unpredictable weather events in recent years have made their line of work even more frustrating than usual.

Over the last five years, the Ontario winemaking area’s grape growers have encountered drought, flooding and even a late spring frost, which have all wreaked havoc on their crops.

“There are people who joke that they’re just waiting for the plague of locusts, and then we’ll be complete and we can just get back to normal,” said Caroline Granger, the owner of the Grange of Prince Edward Vineyards and Estate Winery.

Winegrowers say climate change has made weather patterns so unpredictable in recent years that they cannot rely on grape yield. In an industry that relies so heavily on climate, this has made it difficult to budget and forecast production levels.

Granger said she expects variations from year to year, but the weather of the last five years has been well beyond the normal ebbs and flows. She knows the land and its typical climate well, having built her vineyard and winery on a farm her parents bought in 1974.

Of the last four years, Granger said three of them were impossible to predict.

In 2015, a late spring frost was fairly devastating for grape growers when the temperature dropped to below -5 C. Then in 2017, Granger’s vineyard saw flooding that lasted well into the summer.

This year, the county saw levels of heat and humidity that Granger said were unprecedented. Usually when there is a particularly hot summer, grape growers get a bit of a reprieve from high temperatures in September, but that was not the case this year. The first two weeks of September were very hot and humid, which posed problems as grapes ripened very quickly.

For Keith Tyers, a winemaker at Closson Chase Winery, most of the last ten years have been challenging. He said climate-related issues have changed the way grape growers have approached everything.

“If anyone says climate change or global warming doesn’t exist, just talk to a grape grower. We’ll tell you that nothing’s the same. It’s so inconsistent,” said Tyers.

Prince Edward County’s grape growers are now wrestling with how to deal with the unpredictable weather. Monitoring the weather has always been part of the job description for grape growers, but they have had to pay extra close attention to weather reports in recent years.

Granger and her staff have been inspecting their vines three times more often than they used to, looking for telling variations.

As with other types of farming, Ontario grape growers only get one harvest a year, which means they only get one chance a year to learn something that you can apply to the following season. So any change in method can come slowly and even slower when weather is as unpredictable as it has been in recent years, Granger said.

“It’s a mixed bag situation. You win in some areas and you lose in some areas”

One silver lining of the volatile weather for Granger has been that challenging years have produced some great wines, despite not in the quantities she would have liked.

“As we are working our way through anomalies, weather variation or climate change and each year is quite different from the one before, it makes the wines vary and it makes them interesting,” she said.

While winegrowers lament the fluctuating weather, some researchers say climate change may have some benefits for Ontario winemaking in the future.

Anthony Shaw, a geography professor Brock University, said climate change will bring milder winters, warmer growing seasons and longer frost-free periods. This could be beneficial for some red varieties of grape such as cabernet franc, which typically take longer to reach full maturity, he said.

Shaw said Ontario has already started to see milder winters, but that volatility in weather has accompanied that change. He said it is typically better for winegrowers that winters remain cooler before a gradual transition into fall. But that kind of smooth transition period has been happening less, he said.

“It’s a mixed bag situation. You win in some areas and you lose in some areas,” said Shaw, who is also a fellow at the university’s Cool Climate Oenology and Viticulture Institute.

For grape growers, the prospect of a longer growing season is far from comforting as they continue to deal with erratic weather. Tyers said the only thing grape growers in the area can count on is that the unexpected will happen.

“You look back at the end of the season, discuss what you think you did right, and where you think you can improve, but that’s all you can do,” he said.