Recent official forecasts from GFS and ECMWF models indicate mostly clear skies and northeast winds over Istanbul through September 10, supporting daytime highs near 27–28°C and overnight lows of 18–21°C under stable high-pressure conditions typical for early autumn in the region. This setup favors moderate radiative cooling at night without significant cloud cover or frontal systems to alter temperatures. Model consensus points to a minimum in the 19–21°C range, though slight variations in wind strength or boundary-layer mixing could shift the exact low by a degree or two. With market-implied odds closely split between warmer and cooler thresholds, traders appear focused on the narrow uncertainty in nocturnal cooling rates and the final observational data from local stations. Updated model runs and any late changes in synoptic patterns over the next 48 hours will likely refine these probabilities.