**Trader consensus centers on a 26–27°C overnight low for Shanghai on August 4, 2026, reflecting typical early-August climatology in the city’s subtropical monsoon regime.** Historical data show average daily lows of 25–26.4°C in the first third of August, with urban heat-island effects and high humidity (often 75–80 %) limiting nocturnal radiative cooling and keeping minimum temperatures in the mid- to upper-20s °C. Recent conditions remain consistent with this pattern: ongoing summer warmth, limited cloud cover variability, and no strong cold-air intrusions or typhoon influences evident in model guidance as of early August. **The market’s heavy weighting toward 27°C (50.5 %) and 26°C (23.5 %) aligns with ensemble forecasts from global models projecting only modest day-to-day variation and no significant cooling trend through the first week of the month.** Lower probabilities for 25°C or below (under 20 % combined) indicate traders see little chance of atypical advection or enhanced evaporative cooling, while the modest tail for 29°C+ reflects residual uncertainty in daytime heating carry-over. Updated short-range model runs and official guidance from agencies such as the China Meteorological Administration over the next 48 hours will likely tighten these ranges further as the event window approaches.