http://www.nwhikers.net/ is your best source of information.
A few items:
First, there are a lot of forest fires going on; where it isn't burning, it's smoky.
Second, the general hunting season starts this coming Saturday; plan to wear blaze orange.
Third, the long overdue rainy season is forecast to start this Friday. While we hate to see the end of our extended summer, we'd love to see enough rain to put out all the above-mentioned fires! Areas above 6,000 feet will see snow this weekend, so you probably want to avoid those areas. Be prepared for soggy conditions!
To avoid bear canister areas, skip Olympic National Park and North Cascades National Park (I don't know if NCNP actually requires them yet, but they have been talking about it.) Otherwise, no issues.