Official observations from the National Weather Service at San Francisco International Airport recorded a daily maximum of 73°F on September 5, 2026, aligning precisely with the 72-73°F bin that captured full market consensus. Marine layer stratus and moderate onshore flow from the Pacific suppressed afternoon heating, keeping temperatures near or slightly below the 1991-2020 normal high of 75°F for early September. METAR reports confirmed a peak near 73°F midday before cooling under increasing westerly winds. Only an unanticipated post-event data revision or use of a non-airport station for resolution could alter the outcome, though historical patterns and real-time surface data strongly support the observed range.