Thanks for posting to the message board... it sounds like a fantastic family trip you're planning to the islands...
Here is a previous post about
activities for kids in the San Juan Islands Here are a couple more resources about
things for kids to do on orcas Island , and
things for kids to do on San Juan Island. Also don't forget about
children's activities on Lopez Island.
As you can see from the below screenshot the temperatures in March are not exactly tropical yet...However the rainfall is significantly lower than the peak months of November December and January.









thanks again for posting on the message board... please let him know if you have any more questions.
Family Friendly Places to Stay in the San Juan Islands:
Tour Outfitters for Sea Kayaking and Whale Watching: