Recent National Weather Service forecasts and supporting model guidance indicate overnight lows for San Francisco on August 22 in the upper 50s, driven by persistent marine layer influence and westerly flow that moderates temperatures near the coast. This positions the 58-59°F outcome as a leading implied probability alongside adjacent bins, consistent with climatological averages around 56°F and the recent pattern of stable, mild conditions without significant cooling or warming signals. Uncertainty in exact minimum readings, including potential for localized fog or stronger onshore flow, sustains the notable 45% market weighting on 49°F or below as a lower-probability tail scenario. Updated forecast discussions and observational data ahead of resolution will likely refine these trader assessments.