**Forecast models and official guidance from sources like the National Weather Service point to a minimum temperature near 59°F for San Francisco on August 26, 2026, aligning with the market's leading 58-59°F outcome at 44.5% implied probability.** Persistent marine layer effects, light to moderate onshore westerly winds, and partly cloudy skies are expected to moderate overnight cooling, preventing the low from dropping into the mid-50s or below. Recent observations show overnight lows in the upper 50s, consistent with the climatological average low of 56°F for the date but tempered by current atmospheric stability. Model consensus shows limited variability, with no incoming cold front or strong radiative cooling event to push readings lower, while the absence of heat buildup keeps the upper end capped near 60-61°F. Traders appear to weight these near-term forecast details heavily, producing tight clustering around the 56-61°F range that matches observed conditions and seasonal norms for the Bay Area.