**Short-term forecast uncertainty around summer monsoon patterns in the Sichuan Basin is driving closely matched trader probabilities for Chengdu’s August 7 high temperature, with 31–33 °C outcomes collectively implying roughly 65 % probability.** Persistent high humidity (typically 70–85 %) and scattered afternoon showers or thunderstorms, common in August, can suppress peak readings by limiting solar heating, while brief clear spells allow temperatures to climb toward the upper end of model guidance. Recent model runs show variability in timing and coverage of convection, producing the tight spread between 31 °C (22 %) and 33 °C (17.5 %). Historical climatology places typical August daily maxima near 30–32 °C, with occasional spikes above 34 °C when subsidence or weaker monsoon flow dominates. Updated guidance from the China Meteorological Administration and regional numerical weather prediction ensembles over the next 48 hours will likely narrow the range ahead of market resolution.