I live in Los Carneros, well on the border of it anyway. It’s an area known for cool nights, warm days and lots and lots of wind. Los Carneros means The Ram, as in sheep. Yum. I love lamb, especially with a good Syrah. But that’s another post.
Currently at 6:30 am, it’s 57 degrees outside. Our high expected today is 96. Holy cow (or lamb) that’s a 40 degree difference in one day. That huge temperature fluctuation is one thing that makes this a great area for certain grapes. Pinot Noir and Chardonnay in particular very much enjoy these swings. It gives them a moment to rest. It also allows the grapes to develop slower leading to better concentration and more flavor. Always a good thing.
The wind can do the same thing too. Each grape leaf has tiny fibers on the back and when the wind blows strong these fibers move and essentially tell the vine to slow down, life’s too short, take the afternoon off. If that’s not wine country living, then I don’t know what is.
Los Carneros is the only AVA (American Viticulture Area) to span both Sonoma and Napa valleys. For Napa this area represents nearly all the Chardonnay and Pinot Noir production. The reason is as you head north further into Napa Valley it quickly becomes too hot to successfully grow these thin-skinned grape varietals. On the other hand, Sonoma has several AVA’s where these types of grapes thrive including the well known Russian River Valley.
It’s not uncommon for Russian River to see temperature swings of 40 degrees as well, but generally it is not nearly as windy. Los Carneros is at southern end of two valleys – Napa and Sonoma. As the day moves towards happy hour, the air in the northern part of these valleys begins to heat up and rise. That displaced air needs to be filled in and literally creates a vacuum up the valley sucking cooler air from the Carneros region.
By 5:00 pm (that’s happy hour folks!) on any given summer day, the cooling has already begun in Carneros. It’s not uncommon for this southern region to be 20-plus degrees cooler than the areas in the north. For a lot of visitors that’s counter-intuitive. It’s supposed to get cooler as you go north, not warmer. Ahh, the weather – just one of wine country’s mystifying charms.