Many parts of the Puget Sound region are ideally situated for growing premium wine grapes. The Puget Sound basin is a maritime climate with wet, mild winters and dry summers. Temperatures are moderated by the ocean and the Puget Sound so the Puget Sound basin doesn’t have the extreme temperature swings you might find in other parts of the country. Also, the Puget Sound region is further north than most of the growing regions in Europe, giving us very long growing days during the summer helping us ripen our grapes successfully. Because of the abundant sunshine, relatively cool temperatures and dry summers, Puget Sound grapes attain a purity of varietal flavors found almost nowhere else in the world. Climate
The Puget Sound AVA is a part of cool climate growing region that stretches from southern British Columbia to Eugene, Oregon. On average, SeaTac Airport has about 2050 Growing Degree Days (over the last 57 years) and 37" of rain annually. In the Puget Sound, this is good benchmark to start from since it seems to fall in between the warmer southern areas and the cooler northern ones and rainfall is also in the middle. There will be variations in your local microclimate that will dictate what you can grow. A good comparison in Europe to the Puget Sound might be the Loire valley, near Nantes (Muscadet), the Northern Rhine valley in Germany, Champagne or Chablis.Rain
There is a general misconception that the Puget Sound is rainy and gray throughout the year. This is not true, since the Puget Sound receives less rain annually than many other well known grape growing regions, and we get less than most during the most important growing time of the year (April-October). Rainfall averages for the Puget Sound range anywhere from 16" in Sequim, to 66" in Concrete. Keep in mind that less rainfall doesn't always mean a better place to grow grapes. Generally, it's much cooler in the areas that have less rain than those that have more.
Sunshine
As mentioned above, the Puget Sound region is supposedly a gray, rainy climate, but it's not really at least not when we need to grow grapes. Let have a look at how Western Washington compares to other well known growing regions when it comes to sunshine. Seattle gets more sunshine during the growing season than many regions in France, including Burgundy and Bordeaux. All this sunshine, combined with the lack of rain during the growing season is probably the main reason why we can ripen some of the later ripening grapes mentioned below.
GrapesBecause of the great climate in the Puget Sound basin, we have an abundance of choices for high quality grapes to choose from. Many of the grapes are well known, but some are not widely planted. The most widely planted grapes in the Puget Sound region are Madeleine Angevine, Siegerrebe, Muller-Thurgau, Pinot Noir and Pinot Gris. There are smaller plantings of Melon, Chasselas, Regent and Chardonnay.
Research continues to uncover new earlier ripening grape varieties and new areas west of the Cascades to grow grapes. With time and more growers planting every year, we'll uncover the optimal grapes and locations to grow grapes in the Puget Sound AVA.
The WSU Mt. Vernon research station has many grape varieties on trial. You can see more information about those grape trials at this link: Mt. Vernon Research Station