Is the kids play structure covered from the rain?

On both structures, there is partial cover, but that's mostly for shade from the sun. All the slides are exposed, however, and you'll still get wet if it's raining. My advice would be a good rain jacket, rain boots, and some warm, dry clothes to change into afterwards. It's the PNW, so it rains about 2/3 of the year. The trampoline is great when it gets wet, because it holds the water on the surface, and makes great splashes!

Don't count on protection.

Mostly it's uncovered

There are some small covered areas, but for all practical purposes, no.