It's a popular misconception that the US Pacific Northwest does not have a "fall". That's because most of the trees here are evergreens (cedars and firs being the most common), and so don't have leaves changing color. But there are plenty of pockets of fall, where the colors are quite wonderful, and contrast well with evergreens around them. Fall lasts from mid-late September all through October.
Here's a small photoblog of fall in various stages, taken over the past couple of months.
That is a picture of one of the most well known bike trails around, the 60 mile odd Burkegilman trail, when fall was just beginning.
Here's a contrast of the evergreens, with some fall color on a tree.
This picture is one of my favorites, with the ivy turning red, some trees in fall color, and the evergreens around.
The ground beneath my feet.