**Persistent rainfall from regional tropical low-pressure systems and monsoon influences is the main driver keeping overnight lows in Shenzhen clustered around 25–28°C for August 24.** Multiple official and model forecasts (including Chinese meteorological sources and international models) show moderate to heavy rain continuing through the night, with cloud cover and high humidity (often 85–95%) limiting radiative cooling. This produces minimum temperatures typically in the mid-to-upper 20s Celsius, consistent with the market’s tight distribution favoring 27°C (37%), 28°C (33.5%), and 25°C (30%). Steering patterns and moisture from nearby typhoon activity (noted in local Shenzhen bureau updates) sustain the rain and suppress clear-sky cooling that would otherwise allow lows to drop further. Historical August climatology for Shenzhen features average overnight lows near 27°C, but the current wet regime has kept recent nights warmer than drier analogs. Minor forecast differences in rain timing, intensity, and wind speed create the observed spread across 25–28°C outcomes, as even small variations in cloud cover or precipitation can shift the exact minimum by 1–2°C. New model runs or radar updates over the next 12–24 hours remain the key near-term catalysts for any market movement.