When to Go
Any time of year (Nice park to enjoy in good weather)
Things to Do
Stroll around the park, fly kites, frisbees, pinwheels, go up and down the hill, take a nice picture with downtown Seattle in the backdrop, enjoy the sun, etc.
Tips
1) There is a big event yearly on the 4th of July (Seafair Summer Fourth) at the park with a great view of the fireworks over Lake Union but it may be hard to attend the event with young kids because of the crowd.
2) Strolling around the park while enjoying the view of downtown Seattle acrossLake Union is spectacular.