Kalen,
The average temperature you're looking at accounts for all time points in the day, including chillier morning temps. From weather.com, it says that Tacoma averages 1.58" of rain in June.
While I like warmer temperatures, at least they won't have to worry about extreme heat possible in places such as Pinehurst or Tulsa, OK (and has also happened in Pittsburgh, the DC suburbs, Springfield, NJ, etc.).