Outdoor Exploratorium
Check out the outdoor science project at Ft. Mason before it ends after this weekend. The 20 exhibits include a wave tracer that graphs the currents and tides, a bridge thermometer that shows how much the Golden Gate Bridge expands and contracts, and wind arrows that show how wind direction and speed changes with height. Come Saturday and stay for a view of the fireworks. Friday-Sunday, 7/3-5.

Russian River Water Carnival
Monte Rio is the site of the best pre-4th celebration in the Bay Area, and a great reason to get out of town. The banks of the river are the scene of the Big Rocky Games (innertube race, rock skipping, etc) during the day, while later a float parade winds its way down the shallow water. A giant water curtain and fireworks show follow at dusk. Friday, 7/3, 11am-10pm, Monte Rio.

Fillmore Jazz Festival
As if the weekend wasn’t already loaded, one of the best jazz festivals around features two stages of live music and 12 blocks of vendors and activities on Fillmore. The free festival draws a crowd – more than 100,000 visitors are expected for the two-day event. Saturday-Sunday, 7/4-5, 10am-6pm.

Independence Day Celebrations
Of the day’s many options, here’s my choice: head to Sausalito for the 10am parade, enjoy the festival in Dunphy Park with live music, food, games and tug of war, and stay for the prime viewing of fireworks over the bay, with the bonus of seeing San Francisco’s fireworks just beyond. You can also spend the day in Angel Island to view the display, which offers a special 4th ferry service. Saturday, 7/4, all day.

USS Hornet
My second choice? Spend the 4th aboard an aircraft carrier in SF Bay. The USS Hornet in Alameda hosts an Independence Day party with live music, a flight simulator, bouncy house, and three floors of the museum ship open to exploring. Enjoy some food and watch the fireworks from on deck. Saturday, 7/4, noon-10pm.