Official temperature observations from National Weather Service stations in San Francisco recorded a daily low in the 56-57°F range on September 14, driving the market's near-certain consensus on that bin. Persistent marine layer influence and moderate onshore flow kept overnight temperatures from dropping further, consistent with typical late-summer climatology for the region where coastal cooling prevents sharper declines. With the date now passed and data finalized, revisions are unlikely, though an unprecedented station malfunction or post-hoc quality-control adjustment could theoretically shift the recorded minimum.