A few days ago, @sweetgrass had posted about UW’s record after a bye week. I have added their opponent’s season record to get a more complete picture.
2018 defeated Oregon St 42-23 (home); Oregon St season record 2–10 (1–8 Pac-12)
2017 defeated UCLA 44-23 (home); UCLA season record 6–7 (4–5 Pac-12)
2016 defeated Oregon St 41-17 (home); Oregon St season record 4–8 (3–6 Pac-12)
2015 defeated USC 17-12 (away); USC season record 8–6 (6–3 Pac-12)
2014 defeated Cal 31-7 (away); Cal season record 5–7 (3–6 Pac-12)
2013 defeated Colorado 59-7 (home); Colorado season record 4–8 (1–8 Pac-12)
2012 defeated Stanford 17-13 (home); Stanford season record 12–2 (8–1 Pac-12)
2011 defeated Colorado 52-24 (home); Colorado season record 3–10 (2–7 Pac-12)
Only 2 of their 8 opponents ended the season with a winning record. It is still a commendable feat, but not surprising in the least.