Recent forecast models from sources like GFS and ECMWF indicate minimum temperatures in Istanbul on October 3 will likely fall in the 15–17°C range, driven by persistent northeasterly winds advecting cooler maritime air from the Black Sea alongside widespread cloud cover and showers that limit daytime heating and radiative cooling overnight. These conditions align closely with early-October climatology for the Marmara region, where average lows hover near 16°C amid transitional autumn patterns without strong high-pressure blocking or cold-air outbreaks. Market-implied odds favoring 22°C or higher may reflect uncertainty in short-range model runs or recent warmer anomalies, while the low probability assigned to 12°C or below underscores limited risk of significant cooling. Updated model guidance and official Turkish Meteorological Service briefings over the next 48 hours will likely refine these probabilities ahead of market resolution.