Recent forecast guidance from regional meteorological agencies points to overnight lows near 26–27°C in Shanghai on August 22, driven by persistent subtropical high pressure, elevated humidity from the East Asian monsoon, and the urban heat island effect that limits nocturnal cooling. Typical late-August climatology in the Yangtze Delta shows minimum temperatures clustered around this range, with model consensus favoring no significant cold-air intrusion or heavy rain that would alter the diurnal cycle. Trader emphasis on 27°C reflects these stable conditions and historical data distributions, while lower probabilities for 24°C or below account for the low likelihood of atypical frontal passages before resolution. Updated model runs closer to the date will provide the key signal for any shifts.