San Francisco hosts Fleet Week during the beginning of October each year. This is a spectacular air show that can be seen for free at various locations around the city.
The highlight of the show is when the Blue Angels fly out. Depending upon where you are, they could be skimming the tree tops, flying right over your head. That will give the kids a good thrill.
The Blue Angels will do both a Saturday and Sunday show. After the show, they "park" the jets over at Oakland Airport, by the Oakland Aviation Museum. You can get fairly close to the planes just by walking up to the fence.
Where To Watch
There's quite a few spots to watch the aviation show. If you can get into the city early enough, Crissy Field East Beach is a great place. You'll have a great view of the whole show. If it gets a little boring for the kids, they can play on the beach. But you'll have to get here early because there isn't a lot of parking in the area.
Another option is Treasure Island. It's easy to get on and off of the island. If you sit by the water, facing San Francisco, you'll have a great view of the show. Also, the Blue Angels will skim the tree tops, over your head, at least 4 or 5 times. Parking here can be a little bit difficult if you arrive after the show has started.
We tend to drive into the center of the island and find an empty parking lot. We let the kids skate around on their skateboards and watch the show there. Your view isn't that good because chances are there will be buildings or trees in your way. But if you are just interested in watching the 1 hour Blue Angels show, this would be a good option. You can show up whenever if you choose this option. Most of the people will park by the water.
Last Bit of Advice
You might think about bringing some ear protection for the kids. The Blue Angels fly low low. When they come at you, you almost can't hear them. But after they pass you, you can hear that fuel burning hard.