A perfect day to play in the fountain at the Seattle Center is when it is 76 degrees in Seattle and no cloud in the sky.
It does not get much better than this!
If you are ever in Seattle, this is a great way to have fun with kids for FREE! Follow the directions to the Space Needle and you will easily find the fountain.
With bathrooms nearby, with changing stalls, there is no reason not to bring your swim suit to Seattle.