**Forecast model consensus places Shanghai's overnight minimum near 27°C on August 28 under persistent easterly flow, high humidity, and scattered showers that limit radiational cooling.** Recent observations show nighttime lows holding at 26–28°C amid cloud cover and urban heat retention, consistent with late-summer climatology when the East Asian monsoon trough maintains moist, stable air masses. Differentiating outcomes hinge on subtle shifts in boundary-layer mixing, exact timing of any convective cooling, and station-specific measurement at the official observatory, where even 1°C variations can move resolution across adjacent bins. Ensemble spreads from ECMWF and GFS runs remain modest but reflect typical short-range uncertainty in minimum temperature under these conditions. Updated model guidance and China Meteorological Administration briefings in the next 24–48 hours will likely tighten the range before market resolution.