Official meteorological observations from New York City stations, including JFK and Central Park, recorded a daily maximum of 70°F on September 23, 2026, under northeasterly flow, persistent cloud cover, and post-frontal conditions that suppressed warming below the 73.6°F climatological average. National Weather Service preliminary climatological data and hourly reports confirm this peak without exceeding into the 72°F range, aligning precisely with the market's dominant 70-71°F outcome. While instrument calibration differences or microscale variations could theoretically shift a reading by a degree, multi-station consensus and NWS verification make such revisions improbable. Updated model runs and surface analyses released shortly after the date reinforced these measurements ahead of final resolution.