Forecast models from agencies including the Turkish State Meteorological Service and international ensembles project a minimum temperature near 16°C in Istanbul on October 9 under clear to partly cloudy skies, light southerly winds, and moderate humidity that limits overnight radiational cooling. Recent model runs show tight agreement on daytime highs near 22°C but small spreads in the nocturnal minimum tied to subtle differences in boundary-layer mixing and cloud timing. Historical October lows average 13–15°C, yet the current high-pressure setup favors milder conditions. Market-implied odds cluster tightly around 14–20°C because traders weigh these forecast uncertainties, local urban heat-island effects, and potential last-minute model revisions against the low 2.5% chance of 10°C or below.