Recent model consensus from ECMWF and GFS runs points to overnight radiative cooling under partly cloudy skies and light northeasterly flow, positioning a minimum near 12°C as the most likely outcome for Istanbul on September 25. This aligns with late-September climatology, where typical lows range 14–17°C, though current surface observations showing daytime highs around 21–24°C and dew points near 13°C support further nocturnal drops. Traders appear to weigh the absence of strong warm advection or cloud cover against historical variability, with 11°C as the next most probable if cooling intensifies. Official Turkish Meteorological Service readings expected by early morning will resolve the market.