**An incoming cold front is the main driver behind the closely matched market probabilities for Wuhan's September 17 low temperature.** Northern cold air advection, combined with widespread rain and thunderstorms forecast for September 16–18, is expected to drop daytime highs by roughly 10°C from recent 28–31°C levels, with overnight radiative cooling limited by persistent cloud cover and high humidity. Official and ensemble guidance shows the minimum ranging from about 17–21°C depending on exact rain timing, wind strength, and boundary-layer mixing, creating genuine uncertainty across the 14°C-or-below, 19°C, and 24°C-or-higher outcomes. Traders are pricing in both the potential for stronger cooling under heavier precipitation and the risk of milder conditions if the front weakens or clears earlier. Updated model runs and local meteorological briefings over the next 48 hours will likely sharpen resolution criteria around the observed overnight minimum.