**Persistent summer warmth combined with elevated humidity and light steering winds is limiting nocturnal radiative cooling across the Yangtze River Delta, pushing market-implied probabilities toward 28–29 °C minima for Shanghai on August 8.** Official guidance and ensemble forecasts from regional meteorological centers currently project overnight lows in the 26–28 °C range after daytime highs near 31–34 °C, consistent with the strong trader consensus on the upper side of historical early-August norms (typically 25–26 °C). High moisture content reduces the diurnal temperature range by trapping longwave radiation, while weak easterly flow and urban heat-island effects further suppress cooling under partly cloudy skies. Model spread remains modest at this lead time, with limited signals for stronger cold advection or widespread precipitation that could drop readings toward 27 °C or below. Any late revisions in forecast humidity profiles or unexpected clear-sky development could shift probabilities downward, but current atmospheric conditions favor the warmer outcomes reflected in the closely matched leading contracts. Updated model runs and official briefings over the next 48 hours will provide the next key data points for resolution.