My wife and I love taking our daughter here. Especially when the weather is too poor for the zoo.
The happiest place on earth for our little 4 y/o. There are crafts and a special hangout place for smaller friends to build and climb. We went so much we became donors and now can cut any line. The cafeteria kinda suuuuuux but there are delicious restaurants like Nopalito just a few blocks away! Right now during the winter there is ice skating!!
Holiday activities are on at the Academy! There's an ice rink, indoor "snow flurries" and hands-on polar exhibit. Tickets for ice skating are $10 for members, $12 for non-members. https://www.calacademy.org/exhibits/’tis-the-season-for-science
Often crowded but a lot of fun. Your best bet is to arrive early (members can get an extra morning hour too) and wear everyone out before the museum gets mobbed. The aquarium is a favorite of my boys and they especially love the starfish "petting zoo"! Ask at the information desk about the discovery backpack for kids and get some extra activities to do.
This was the first membership we got once we moved here to SF. The lines can be really long, and the tickets for an adult are close to $40! So the membership is really worth the money spent. The member line is always so short too. This place is the perfect rainy/foggy day activity! Equipped with a huge aquarium and a butterfly exhibit, your lo will not get bored for one second.