SF will launch fireworks from the Golden Gate Bridge on July 4 at 9:30 p.m. — only the third time in the span's history, and the first since 2012. The problem: July 4 is peak fog season, and no contingency plan has been announced.

San Francisco will launch fireworks from the Golden Gate Bridge on Saturday, July 4, at 9:30 p.m. — only the third time in the bridge's 90-year history that pyrotechnics have gone up from the span itself. Mayor Daniel Lurie announced the show on June 15. It's free.

The previous two times were the bridge's 50th anniversary in 1987 and its 75th in 2012. This one marks America's 250th. Shells will fire from the bridge's east side between both towers, with two additional barges — one positioned off the bridge, one near Pier 39 — meaning the display will be visible from a wide sweep of the northern waterfront. The Embarcadero, Crissy Field, Marina Green, Aquatic Park, Pier 39, Fisherman's Wharf, and rooftops in the Marina, Russian Hill, and North Beach all have angles on it.

The one problem: it's July. SF's signature fog doesn't take national holidays off — July 4 is deep inside Karl's peak season. The 2012 show launched from the bridge on May 27 under noticeably clearer skies. No contingency date or threshold for calling it foggy-enough-to-punt has been announced publicly.

Logistics, which are significant: The bridge closes to all vehicle traffic at 8:30 p.m. July 4. The east sidewalk closes July 3 at 5 a.m. through July 5 at 5 a.m. for staging. The west sidewalk closes July 4 from 8 p.m. to 10 p.m. Marina Green and Crissy Field parking closes at 6 a.m. July 4 (not a typo — the whole day), and all bridge south-end parking follows at 11 a.m. Transit is the move.

The actual move if you can swing it: Marin side. Battery Spencer above Fort Baker and Hawk Hill on Conzelman Road both sit above the fog line more reliably than the SF waterfront, and the view looks straight down the bridge's length. Neither has much parking on a normal night; on July 4, get there in the early afternoon or seriously consider biking in. If you're staying on the SF side, Crissy Field is the spot — but plan on arriving well before 9 p.m. and walking in.

No word yet on whether the city has a fog contingency. Consult the forecast by July 3.