**Official observations from the National Weather Service confirmed a minimum temperature of 55°F at San Francisco International Airport (KSFO) on August 26, 2026, aligning closely with the market's dominant 56–57°F outcome at near-100% implied probability.** This positioning reflects the strong scientific consensus from verified METAR and climate reports showing overnight lows in the mid-50s°F under typical late-summer marine layer conditions, with dew points around 54–55°F and light winds preventing further radiative cooling. The slight deviation from the long-term normal low of 56°F (1991–2020 baseline) was driven by persistent onshore flow and fog/haze, which moderated temperatures without allowing a dip into the low 50s. Historical analogs for the date rarely produce readings below 53°F absent unusual synoptic patterns, reinforcing trader confidence in the observed range. Realistic scenarios that could have challenged this include a stronger offshore wind event or clearer skies enabling greater radiational cooling, potentially dropping the official minimum to 54°F or below—but no such shift materialized in the latest model guidance or real-time data.