where are the rainforests in Oregon

Just up the road from Port Angeles on the Olympic Peninsular. It is a lovely trip. Highway 101 in that area is two lanes but well traveled and last time we went well maintained. Lots of nice places to visit, like Squim, and our favorite, Rest-A-While RV park on the Hood River Canal.
Enjoy

downtown portland october till august

Up here in WA on the Olympic Peninsula, coastal side. :)

Rain forests in Oregon? None.
You will find coastal, valley, both temerate climates. Mountains of the Cascades with passes ranging from 4 to 5 thousand feet. And the high desert regions of central and eastern Oregon, but no rain forest. That is in NW Washington state, commonly called the Olympic pennisula.