San Francisco's coastal location along the cold California Current and persistent marine layer typically moderate summer lows into the upper 50s°F, with official National Weather Service observations confirming a minimum of 58–59°F on August 23. This outcome aligns with the city's climatological baseline for late August, where onshore flow and fog suppress daytime heat while preventing significant overnight cooling. Trader consensus at 100% reflects verified station data rather than forecasts, leaving little room for revision. Only an undocumented station anomaly or post-hoc data correction could alter the result, both highly improbable given standard reporting protocols.