Trader consensus around 20–22°C for Istanbul’s lowest temperature on August 28 reflects model consensus under persistent high pressure and light winds that limit overnight radiative cooling in late summer. Small edges for 21°C stem from ensemble guidance showing modest humidity increases and partial cloud cover that temper temperature drops, while slightly lower probabilities for 20°C or 19°C hinge on any late-model shift toward clearer skies allowing greater heat loss. Forecasters from the Turkish State Meteorological Service and ECMWF runs highlight the narrow range driven by typical seasonal baselines near 20–22°C, with resolution depending on final observational data from local stations. New model updates through August 27 could adjust these tight probabilities as steering patterns stabilize.