Traders are pricing the NYC low temperature on September 16 most heavily in the 62–65°F range because ensemble guidance from the GFS and ECMWF shows a transitional air mass with limited nocturnal cooling under partly cloudy skies and light northerly flow. Key differentiating factors include the strength of radiative cooling after sunset, which depends on cloud cover and dewpoint depression, versus mixing from any residual sea breeze or weak frontal passage that could hold temperatures a few degrees higher. Historical mid-September climatology places the typical overnight low near 60–63°F, providing a baseline against which current model spreads of roughly ±3–5°F create the observed tight clustering of probabilities. Updated NWS forecast discussions and next model cycles will likely refine these odds as the 48-hour window narrows.