If you need a place to stay in Ballard I highly recommend Edward’s accommodation. It’s just minutes by foot from Market St and you can also easily catch the D line to be downtown in about 30 minutes. The room was excellent, with one of the most comfortable beds I’ve ever slept in, and all of the facilities were very clean and well-kept. Just be sure to allow enough time (and money if taking an Uber) to get back and forth from the airport as it is quite far.