Traders assign nearly identical implied probabilities to minimum temperatures of 22°C and 23°C in Istanbul on August 22 because short-range ensemble forecasts show a tight spread of possible overnight lows centered near those values. Typical August climatology for the city features average lows of 20–22°C, modulated by radiative cooling under clear or partly cloudy skies, light winds, and the moderating influence of the Bosphorus and Marmara Sea. Key differentiating factors include model differences in boundary-layer mixing, humidity profiles, and urban heat-island effects, which can alter the nocturnal temperature drop by 1–2°C. Updated ECMWF and local meteorological service runs, along with fresh observational data, remain the primary catalysts that could narrow or widen these closely matched outcomes before resolution.