Forecast models from sources including the Met Office and regional ensembles show a consensus for Istanbul highs of 19–20°C on October 4 under building high pressure, clear to partly cloudy skies, and moderate northeast winds. This aligns with the market’s heavy weighting toward those outcomes at 57% and 37.5% implied probability, respectively. Autumnal conditions typical for early October—declining solar angles and average seasonal maxima near 19°C—limit upside potential, keeping 21°C or higher at just 4.5%. Recent showers on October 2–3 are expected to clear, reducing cloud cover and supporting the mild range without significant warming or cooling anomalies. Final model runs and observational updates in the next 48 hours will refine resolution criteria for the daily maximum.