Incoming cold air advection from the north, combined with widespread cloud cover and moderate to heavy rainfall, is the main driver suppressing daytime maximum temperatures in Wuhan on September 17. Official guidance from the Wuhan Meteorological Observatory and global models point to a high near 22°C amid northeasterly winds and 70–90% rain probability, sharply lower than the 29–31°C readings of the prior days. This frontal passage enhances evaporative cooling and reduces insolation, tightening the distribution of plausible highs. Ensemble forecasts show modest spread, with some runs favoring 21–23°C under sustained overcast conditions while others allow brief clearing to push toward 24°C. Traders are weighting these near-term model trends heavily, as resolution hinges on the precise timing and intensity of the rain band tracked by the China Meteorological Administration.