**Current forecasts from multiple meteorological sources, including GFS and regional models, indicate a highest temperature in Istanbul on September 4 most likely in the 26–28°C range.** Northeast winds (poyraz) and increasing cloud cover or scattered showers—consistent with an incoming frontal system noted by Turkish authorities (AKOM/Meteoroloji)—are expected to moderate daytime heating, preventing stronger warming while limiting extreme cooling. Model consensus shows daytime maxima near 28°C early in the period transitioning to 27–29°C on the 4th under partly cloudy skies, with precipitation chances rising later in the day. This aligns with climatological norms for early September in the region, where highs typically average 23–27°C amid transitioning seasonal patterns. The market’s heavy weighting toward 26°C reflects trader assessment of these cooling influences and model spreads, while lower probabilities for 25°C or 27°C capture remaining forecast uncertainty in timing and intensity of any rain or cloud build-up. Updated model runs and official briefings over the next 24–48 hours will likely refine these implied probabilities.