I was struck recently by a headline posted recently by a Seattle-dwelling friend of mine: Seattle just broke a 122-year-old record for rain. The total rainfall for this famously rainy city between October 2016 and April 2017? 44.67".
Here at Tablas Creek, over the same period, we've received 41.57" of rain. No, you aren't reading that wrong. The rainfall we've received this past winter would be one of the wettest winters ever recorded in Seattle. So perhaps it shouldn't be surprising that the below landscape (taken down near our creek a few months ago) could be straight out of the Pacific Northwest:
And while 2016-17 was quite a wet winter here, winters like it aren't all that rare. Looking just over the last 20 years, this is the fifth winter that our weather station recorded 37" or more of rainfall here:
Although the winter of 2016-17 was an outlier, our average rainfall here at the vineyard (25") is still pretty wet. Other areas that average 25" of rain include lots of places in the upper Midwest, Texas, and northern California. Also Chateauneuf du Pape, Alsace, and Burgundy. What makes our rainfall here extraordinary is that almost all of our rain comes in a six-month period between November and April. Take a look at our average rainfall by month at the vineyard:
During the six wet months, we get 92% of our annual rainfall and average 3.82" of rain per month. If we were to extrapolate this to an annual basis, that's nearly 46" of rain, which you see in climates like New York City, Boston, Columbia MO, and Wilmington NC. Seattle, by contrast, receives 38" per year.
If you look on the flip side at our six dry months, we average 0.35" of rain per month May-October. On an annual basis, that's 4.14", slightly less than the city of Las Vegas (5") and slightly more than Lake Havasu, AZ (3.8").
How unusual is this rainfall distribution for a wine region? Extremely. Take a look at three regions in Europe. First, Dijon, in the heart of Burgundy, which receives nearly the same amount of rainfall on an annual basis as we do, but with an almost-equal distribution each month (note that these graphs are all from the fascinating site climate-data.org, on which you can find similar information for thousands of locations around the globe):
Maybe a more Mediterranean region like Tuscany? The city of Florence sees about the same amount of rain we receive on an annual basis, and a distribution with slightly drier summers than winters, but nothing close to the degree we see here:
Chateauneuf du Pape is a better match still, though their two rainiest months are September-October:
In order to find an Old World rainfall distribution similar to ours, you have to go all the way into the Eastern Mediterranean. The Bekaa Valley in Lebanon would be a great match, if they only received 175% as much rain as they do:
OK, that was a lot of graphs. But it's important, I think, if you're trying to wrap your head around the climate here in west Paso Robles, to pay just as much attention to the winters (wet) and nights (cold) as one does to the dry, hot summer days. For visitors who come during the summer, the heat and dry landscape can make the cool green hillsides of winter seem like a mirage. But they are two facets of this same climate: a climate in which massive oak trees grow draped with lichen, and in which dry-farmed grapevines can reach down 20 feet into limestone clay to pull out enough moisture to survive through five months of negligible precipitation. As a bonus, it rarely rains during the harvest season, when the grapes are vulnerable.
Desert in the summer, and rain forest in the winter? We'll take it. Even if it is hard to believe.