Quick Guide: May through August in Oregon

Depending on what region you're visiting—the hot south or the more temperate north—summer can be either dry and hot, or more humid and hot. But either way, you'll likely be plenty warm, so pack for the weather.
In the northern most Willamette Valley, rain is still a very real possibility through the summer, so you'll also want to consider something rain-proof, even if you don't end up needing it. It's best to be prepared, however.

Current Portland Weather

What to pack
Layers are always a solid choice for any Oregon trip. Mornings and evenings tend to be cool, even in the more desert-like south, and sweaters and jackets are a good idea. During the day, wear loose-fitting, casual clothing. There's no need for dressing up, or heels. Remember that you'll be visiting mostly rural, agricultural areas that are sometimes accessible only by dirt or gravel roads, and doing a fair amount of walking to and from the vineyards and tasting rooms sometimes. Wear comfortable shoes, and a variety of clothing, like a short sleeve shirt, linen pants or khakis (shorts are fine, but you'll feel most comfortable in longer, non-cut-off versions), and bring along a jacket if things cool off.

Dining Style
As in most of the West Coast, there's rarely an occasion you'll need a tie or sport jacket. Even the most sophisticated restaurants usually welcome diners dressed in pretty much anything appropriate for a casual office environment: slacks and a sweater, a comfortable skirt, pants, whatever—though for really upscale dining its best to avoid jeans if possible.

The People You'll Meet
The folks in Oregon are some of the friendliest, most welcoming in Wine Country. Despite the popularity of Pinot Noir from this region (and its prices!) most folks at the wineries are eager for tourists and will go out of their way to accommodate new comers. Ask around for great dining tips, an offbeat attraction or which other wineries in the region you should visit. You'll likely get a knowledgeable, friendly answer. Like other emerging wine regions, members of the winemaker's family, or the winemaker themselves, may be pouring for you. Be sure to ask plenty of questions. Most other tasters visiting in Oregon's wine regions are still learning about wine themselves (unlike some other wine regions) and are eager to find out more about their favorite pours.

Typical temperatures
Mornings and evenings can be cool, but daytime temperatures can range anywhere from the high 70's all the way to the 100's. Inland areas tend to be hotter and drier, as are regions further south. Humidity can be a factor in the northern most regions, as well as along the coast.