Rain in SF! Any ideas for weekend entertainment when the parents are visiting?

My parents are visiting SF this weekend. I had planned on taking them over the golden gate for a hike to the tourist club, but it looks like it will be rainy tomorrow.

Looking for other ideas! They are in their 50s and are moderate drinkers. Not into the art / museum scene so much (MOMA probably not in the cards), although academy of sciences may work.

Go away rain.