The closely matched probabilities across temperature bins around 23–24°C reflect substantial uncertainty in short-range ensemble forecasts for Shanghai’s minimum temperature on September 11, as global models show modest spread in boundary-layer cooling under partly cloudy skies and light northerly flow. Historical September lows average near 22°C, but recent northerly winds and variable moisture from the western Pacific subtropical high have produced overnight temperatures in the low-to-mid 20s°C, with limited cold-air advection expected in the next 48 hours. Key variables include cloud-cover timing that modulates radiative cooling and any subtle strengthening of the high-pressure ridge, both of which can shift the outcome by 1–2°C. Updated runs from the GFS and ECMWF ensembles, plus official guidance from the China Meteorological Administration, are due within the next 24 hours and will likely narrow the market-implied range.