Coastal moderation from the Yellow Sea, combined with expected cloud cover, light showers, and northeasterly flow, anchors trader-implied odds around 28–31°C for Qingdao’s August 20 high. Short-term numerical weather prediction guidance shows daily maxima near 27–31°C, consistent with historical August averages of ~29–30°C and recent observations under similar maritime regimes. Sea breezes and high humidity limit daytime heating, while precipitation timing and boundary-layer mixing introduce modest variability that supports the market’s tight clustering on 29°C (33%), 30°C (24%), and 31°C (21%). Updated model runs and official China Meteorological Administration briefings over the next 48 hours remain key catalysts that could shift probabilities if drier or sunnier conditions develop.