Current forecast models from sources including ECMWF and regional guidance indicate a minimum temperature for Guangzhou on September 20 near 24–27°C under partly cloudy to thundery conditions, with highs reaching 33–35°C. This positioning reflects typical late-summer subtropical patterns, where daytime heating and high humidity limit nocturnal radiative cooling while scattered convection or lingering cloud cover can suppress the overnight low by 1–3°C relative to clear-sky baselines. Historical averages for the date hover around 23.8°C, yet recent model consensus shows limited spread for extremes below 22°C or above 30°C, consistent with the near-even market split between the 21°C-or-below and 31°C-or-higher bins. Key variables include steering flow strength, which could enhance or reduce thunderstorm timing and thus minimum readings, and urban heat-island effects that often elevate observed lows. Updated short-range runs and official briefings over the next 48 hours will refine these thresholds ahead of market resolution.